Hari Manoharan

All Publications

• Nanoscale Electronic Transparency of Wafer-Scale Hexagonal Boron Nitride. Nano letters Zerger, C. Z., Rodenbach, L. K., Chen, Y., Safvati, B., Brubaker, M. Z., Tran, S., Chen, T., Li, M., Li, L., Goldhaber-Gordon, D., Manoharan, H. C. 2022

  Abstract

  Monolayer hexagonal boron nitride (hBN) has attracted interest as an ultrathin tunnel barrier or environmental protection layer. Recently, wafer-scale hBN growth on Cu(111) was developed for semiconductor chip applications. For basic research and technology, understanding how hBN perturbs underlying electronically active layers is critical. Encouragingly, hBN/Cu(111) has been shown to preserve the Cu(111) surface state (SS), but it was unknown how tunneling into this SS through hBN varies spatially. Here, we demonstrate that the Cu(111) SS under wafer-scale hBN is homogeneous in energy and spectral weight over nanometer length scales and across atomic terraces. In contrast, a new spectral feature─not seen on bare Cu(111)─varies with atomic registry and shares the spatial periodicity of the hBN/Cu(111) moire. This work demonstrates that, for some 2D electron systems, an hBN overlayer can act as a protective yet remarkably transparent window on fragile low-energy electronic structure below.

  View details for DOI 10.1021/acs.nanolett.1c04274

  View details for PubMedID 35536749

• Signatures of two-dimensional superconductivity emerging within a three-dimensional host superconductor. Proceedings of the National Academy of Sciences of the United States of America Parra, C., Niestemski, F. C., Contryman, A. W., Giraldo-Gallo, P., Geballe, T. H., Fisher, I. R., Manoharan, H. C. 2021; 118 (16)

  Abstract

  Spatial disorder has been shown to drive two-dimensional (2D) superconductors to an insulating phase through a superconductor-insulator transition (SIT). Numerical calculations predict that with increasing disorder, emergent electronic granularity is expected in these materials-a phenomenon where superconducting (SC) domains on the scale of the material's coherence length are embedded in an insulating matrix and coherently coupled by Josephson tunneling. Here, we present spatially resolved scanning tunneling spectroscopy (STS) measurements of the three-dimensional (3D) superconductor BaPb1-x Bi x O3 (BPBO), which surprisingly demonstrate three key signatures of emergent electronic granularity, having only been previously conjectured and observed in 2D thin-film systems. These signatures include the observation of emergent SC domains on the scale of the coherence length, finite energy gap over all space, and strong enhancement of spatial anticorrelation between pairing amplitude and gap magnitude as the SIT is approached. These observations are suggestive of 2D SC behavior embedded within a conventional 3D s-wave host, an intriguing but still unexplained interdimensional phenomenon, which has been hinted at by previous experiments in which critical scaling exponents in the vicinity of a putative 3D quantum phase transition are consistent only with dimensionality d = 2.

  View details for DOI 10.1073/pnas.2017810118

  View details for PubMedID 33846248

• Quantum engineered Kondo lattices. Nature communications Figgins, J. n., Mattos, L. S., Mar, W. n., Chen, Y. T., Manoharan, H. C., Morr, D. K. 2019; 10 (1): 5588

  Abstract

  Atomic manipulation techniques have provided a bottom-up approach to investigating the unconventional properties and complex phases of strongly correlated electron materials. By engineering artificial systems containing tens to thousands of atoms with tailored electronic or magnetic properties, it has become possible to explore how quantum many-body effects emerge as the size of a system is increased from the nanoscale to the mesoscale. Here we investigate both theoretically and experimentally the quantum engineering of nanoscale Kondo lattices - Kondo droplets - exemplifying nanoscopic replicas of heavy-fermion materials. We demonstrate that by changing a droplet's real-space geometry, we can not only create coherently coupled Kondo droplets whose properties asymptotically approach those of a quantum-coherent Kondo lattice, but also markedly increase or decrease the droplet's Kondo temperature. Furthermore we report on the discovery of a new quantum phenomenon - the Kondo echo - a signature of droplets containing Kondo holes functioning as direct probes of spatially extended, quantum-coherent Kondo cloud correlations.

  View details for DOI 10.1038/s41467-019-13446-1

  View details for PubMedID 31811123

• Phase Separation of Dirac Electrons in Topological Insulators at the Spatial Limit NANO LETTERS Parra, C., Rodrigues da Cunha, T. H., Contryrnan, A. W., Kong, D., Montero-Silva, F., Rezende Goncalves, P. H., dos Reis, D. D., Giraldo-Gallo, P., Segura, R., Olivares, F., Niestemski, F., Cui, Y., Magalhaes-Paniago, R., Manoharan, H. C. 2017; 17 (1): 97-103

  Abstract

  In this work we present unique signatures manifested by the local electronic properties of the topological surface state in Bi2Te3 nanostructures as the spatial limit is approached. We concentrate on the pure nanoscale limit (nanoplatelets) with spatial electronic resolution down to 1 nm. The highlights include strong dependencies on nanoplatelet size: (1) observation of a phase separation of Dirac electrons whose length scale decreases as the spatial limit is approached, and (2) the evolution from heavily n-type to lightly n-type surface doping as nanoplatelet thickness increases. Our results show a new approach to tune the Dirac point together with reduction of electronic disorder in topological insulator (TI) nanostructured systems. We expect our work will provide a new route for application of these nanostructured Dirac systems in electronic devices.

  View details for DOI 10.1021/acs.nanolett.6b03506

  View details for Web of Science ID 000392036600015

  View details for PubMedID 28026959

• Activating and optimizing MoS2 basal planes for hydrogen evolution through the formation of strained sulphur vacancies NATURE MATERIALS Li, H., Tsai, C., Koh, A. L., Cai, L., Contryman, A. W., Fragapane, A. H., Zhao, J., Han, H. S., Manoharan, H. C., Abild-Pedersen, F., Norskov, J. K., Zheng, X. 2016; 15 (1): 48-?

  Abstract

  As a promising non-precious catalyst for the hydrogen evolution reaction (HER; refs ,,,,), molybdenum disulphide (MoS2) is known to contain active edge sites and an inert basal plane. Activating the MoS2 basal plane could further enhance its HER activity but is not often a strategy for doing so. Herein, we report the first activation and optimization of the basal plane of monolayer 2H-MoS2 for HER by introducing sulphur (S) vacancies and strain. Our theoretical and experimental results show that the S-vacancies are new catalytic sites in the basal plane, where gap states around the Fermi level allow hydrogen to bind directly to exposed Mo atoms. The hydrogen adsorption free energy (ΔGH) can be further manipulated by straining the surface with S-vacancies, which fine-tunes the catalytic activity. Proper combinations of S-vacancy and strain yield the optimal ΔGH = 0 eV, which allows us to achieve the highest intrinsic HER activity among molybdenum-sulphide-based catalysts.

  View details for DOI 10.1038/NMAT4465

  View details for Web of Science ID 000366690600019

  View details for PubMedID 26552057

• Optoelectronic crystal of artificial atoms in strain-textured molybdenum disulphide NATURE COMMUNICATIONS Li, H., Contryman, A. W., Qian, X., Ardakani, S. M., Gong, Y., Wang, X., Weisse, J. M., Lee, C. H., Zhao, J., Ajayan, P. M., Li, J., Manoharan, H. C., Zheng, X. 2015; 6

  Abstract

  The isolation of the two-dimensional semiconductor molybdenum disulphide introduced a new optically active material possessing a band gap that can be facilely tuned via elastic strain. As an atomically thin membrane with exceptional strength, monolayer molybdenum disulphide subjected to biaxial strain can embed wide band gap variations overlapping the visible light spectrum, with calculations showing the modified electronic potential emanating from point-induced tensile strain perturbations mimics the Coulomb potential in a mesoscopic atom. Here we realize and confirm this 'artificial atom' concept via capillary-pressure-induced nanoindentation of monolayer molybdenum disulphide from a tailored nanopattern, and demonstrate that a synthetic superlattice of these building blocks forms an optoelectronic crystal capable of broadband light absorption and efficient funnelling of photogenerated excitons to points of maximum strain at the artificial-atom nuclei. Such two-dimensional semiconductors with spatially textured band gaps represent a new class of materials, which may find applications in next-generation optoelectronics or photovoltaics.

  View details for DOI 10.1038/ncomms8381

  View details for Web of Science ID 000357175300014

  View details for PubMedID 26088550

• Optoelectronic crystal of artificial atoms in strain-textured molybdenum disulphide. Nature communications Li, H., Contryman, A. W., Qian, X., Ardakani, S. M., Gong, Y., Wang, X., Weisse, J. M., Lee, C. H., Zhao, J., Ajayan, P. M., Li, J., Manoharan, H. C., Zheng, X. 2015; 6: 7381-?

  Abstract

  The isolation of the two-dimensional semiconductor molybdenum disulphide introduced a new optically active material possessing a band gap that can be facilely tuned via elastic strain. As an atomically thin membrane with exceptional strength, monolayer molybdenum disulphide subjected to biaxial strain can embed wide band gap variations overlapping the visible light spectrum, with calculations showing the modified electronic potential emanating from point-induced tensile strain perturbations mimics the Coulomb potential in a mesoscopic atom. Here we realize and confirm this 'artificial atom' concept via capillary-pressure-induced nanoindentation of monolayer molybdenum disulphide from a tailored nanopattern, and demonstrate that a synthetic superlattice of these building blocks forms an optoelectronic crystal capable of broadband light absorption and efficient funnelling of photogenerated excitons to points of maximum strain at the artificial-atom nuclei. Such two-dimensional semiconductors with spatially textured band gaps represent a new class of materials, which may find applications in next-generation optoelectronics or photovoltaics.

  View details for DOI 10.1038/ncomms8381

  View details for PubMedID 26088550

• Stripe-like nanoscale structural phase separation in superconducting BaPb1-xBixO3. Nature communications Giraldo-Gallo, P., Zhang, Y., Parra, C., Manoharan, H. C., Beasley, M. R., Geballe, T. H., Kramer, M. J., Fisher, I. R. 2015; 6: 8231-?

  Abstract

  The phase diagram of BaPb1-xBixO3 exhibits a superconducting dome in the proximity of a charge density wave phase. For the superconducting compositions, the material coexists as two structural polymorphs. Here we show, via high-resolution transmission electron microscopy, that the structural dimorphism is accommodated in the form of partially disordered nanoscale stripes. Identification of the morphology of the nanoscale structural phase separation enables determination of the associated length scales, which we compare with the Ginzburg-Landau coherence length. We find that the maximum Tc occurs when the superconducting coherence length matches the width of the partially disordered stripes, implying a connection between the structural phase separation and the shape of the superconducting dome.

  View details for DOI 10.1038/ncomms9231

  View details for PubMedID 26373890

• Stripe-like nanoscale structural phase separation in superconducting BaPb(1-x)Bi(x)O3. Nature communications Giraldo-Gallo, P., Zhang, Y., Parra, C., Manoharan, H. C., Beasley, M. R., Geballe, T. H., Kramer, M. J., Fisher, I. R. 2015; 6: 8231-?

  Abstract

  The phase diagram of BaPb1-xBixO3 exhibits a superconducting dome in the proximity of a charge density wave phase. For the superconducting compositions, the material coexists as two structural polymorphs. Here we show, via high-resolution transmission electron microscopy, that the structural dimorphism is accommodated in the form of partially disordered nanoscale stripes. Identification of the morphology of the nanoscale structural phase separation enables determination of the associated length scales, which we compare with the Ginzburg-Landau coherence length. We find that the maximum Tc occurs when the superconducting coherence length matches the width of the partially disordered stripes, implying a connection between the structural phase separation and the shape of the superconducting dome.

  View details for DOI 10.1038/ncomms9231

  View details for PubMedID 26373890

• Unconventional molecule-resolved current rectification in diamondoid-fullerene hybrids NATURE COMMUNICATIONS Randel, J. C., Niestemski, F. C., Botello-Mendez, A. R., Mar, W., Ndabashimiye, G., Melinte, S., Dahl, J. E., Carlson, R. M., Butova, E. D., Fokin, A. A., Schreiner, P. R., Charlier, J., Manoharan, H. C. 2014; 5

  Abstract

  The unimolecular rectifier is a fundamental building block of molecular electronics. Rectification in single molecules can arise from electron transfer between molecular orbitals displaying asymmetric spatial charge distributions, akin to p-n junction diodes in semiconductors. Here we report a novel all-hydrocarbon molecular rectifier consisting of a diamantane-C60 conjugate. By linking both sp(3) (diamondoid) and sp(2) (fullerene) carbon allotropes, this hybrid molecule opposingly pairs negative and positive electron affinities. The single-molecule conductances of self-assembled domains on Au(111), probed by low-temperature scanning tunnelling microscopy and spectroscopy, reveal a large rectifying response of the molecular constructs. This specific electronic behaviour is postulated to originate from the electrostatic repulsion of diamantane-C60 molecules due to positively charged terminal hydrogen atoms on the diamondoid interacting with the top electrode (scanning tip) at various bias voltages. Density functional theory computations scrutinize the electronic and vibrational spectroscopic fingerprints of this unique molecular structure and corroborate the unconventional rectification mechanism.

  View details for DOI 10.1038/ncomms5877

  View details for Web of Science ID 000342983300004

  View details for PubMedCentralID PMC4164769

• Unconventional molecule-resolved current rectification in diamondoid-fullerene hybrids. Nature communications Randel, J. C., Niestemski, F. C., Botello-Mendez, A. R., Mar, W., Ndabashimiye, G., Melinte, S., Dahl, J. E., Carlson, R. M., Butova, E. D., Fokin, A. A., Schreiner, P. R., Charlier, J., Manoharan, H. C. 2014; 5: 4877-?

  Abstract

  The unimolecular rectifier is a fundamental building block of molecular electronics. Rectification in single molecules can arise from electron transfer between molecular orbitals displaying asymmetric spatial charge distributions, akin to p-n junction diodes in semiconductors. Here we report a novel all-hydrocarbon molecular rectifier consisting of a diamantane-C60 conjugate. By linking both sp(3) (diamondoid) and sp(2) (fullerene) carbon allotropes, this hybrid molecule opposingly pairs negative and positive electron affinities. The single-molecule conductances of self-assembled domains on Au(111), probed by low-temperature scanning tunnelling microscopy and spectroscopy, reveal a large rectifying response of the molecular constructs. This specific electronic behaviour is postulated to originate from the electrostatic repulsion of diamantane-C60 molecules due to positively charged terminal hydrogen atoms on the diamondoid interacting with the top electrode (scanning tip) at various bias voltages. Density functional theory computations scrutinize the electronic and vibrational spectroscopic fingerprints of this unique molecular structure and corroborate the unconventional rectification mechanism.

  View details for DOI 10.1038/ncomms5877

  View details for PubMedID 25202942

• Artificial honeycomb lattices for electrons, atoms and photons NATURE NANOTECHNOLOGY Polini, M., Guinea, F., Lewenstein, M., Manoharan, H. C., Pellegrini, V. 2013; 8 (9): 625-633

  Abstract

  Artificial honeycomb lattices offer a tunable platform for studying massless Dirac quasiparticles and their topological and correlated phases. Here we review recent progress in the design and fabrication of such synthetic structures focusing on nanopatterning of two-dimensional electron gases in semiconductors, molecule-by-molecule assembly by scanning probe methods and optical trapping of ultracold atoms in crystals of light. We also discuss photonic crystals with Dirac cone dispersion and topologically protected edge states. We emphasize how the interplay between single-particle band-structure engineering and cooperative effects leads to spectacular manifestations in tunnelling and optical spectroscopies.

  View details for DOI 10.1038/NNANO.2013.161

  View details for Web of Science ID 000324172800009

  View details for PubMedID 24002076

• Designer Dirac fermions and topological phases in molecular graphene NATURE Gomes, K. K., Mar, W., Ko, W., Guinea, F., Manoharan, H. C. 2012; 483 (7389): 306-310

  Abstract

  The observation of massless Dirac fermions in monolayer graphene has generated a new area of science and technology seeking to harness charge carriers that behave relativistically within solid-state materials. Both massless and massive Dirac fermions have been studied and proposed in a growing class of Dirac materials that includes bilayer graphene, surface states of topological insulators and iron-based high-temperature superconductors. Because the accessibility of this physics is predicated on the synthesis of new materials, the quest for Dirac quasi-particles has expanded to artificial systems such as lattices comprising ultracold atoms. Here we report the emergence of Dirac fermions in a fully tunable condensed-matter system-molecular graphene-assembled by atomic manipulation of carbon monoxide molecules over a conventional two-dimensional electron system at a copper surface. Using low-temperature scanning tunnelling microscopy and spectroscopy, we embed the symmetries underlying the two-dimensional Dirac equation into electron lattices, and then visualize and shape the resulting ground states. These experiments show the existence within the system of linearly dispersing, massless quasi-particles accompanied by a density of states characteristic of graphene. We then tune the quantum tunnelling between lattice sites locally to adjust the phase accrual of propagating electrons. Spatial texturing of lattice distortions produces atomically sharp p-n and p-n-p junction devices with two-dimensional control of Dirac fermion density and the power to endow Dirac particles with mass. Moreover, we apply scalar and vector potentials locally and globally to engender topologically distinct ground states and, ultimately, embedded gauge fields, wherein Dirac electrons react to 'pseudo' electric and magnetic fields present in their reference frame but absent from the laboratory frame. We demonstrate that Landau levels created by these gauge fields can be taken to the relativistic magnetic quantum limit, which has so far been inaccessible in natural graphene. Molecular graphene provides a versatile means of synthesizing exotic topological electronic phases in condensed matter using tailored nanostructures.

  View details for DOI 10.1038/nature10941

  View details for Web of Science ID 000301481800043

  View details for PubMedID 22422264

• Laser-Synthesized Epitaxial Graphene ACS NANO Lee, S., Toney, M. F., Ko, W., Randel, J. C., Jung, H. J., Munakata, K., Lu, J., Geballe, T. H., Beasley, M. R., Sinclair, R., Manoharan, H. C., Salleo, A. 2010; 4 (12): 7524-7530

  Abstract

  Owing to its unique electronic properties, graphene has recently attracted wide attention in both the condensed matter physics and microelectronic device communities. Despite intense interest in this material, an industrially scalable graphene synthesis process remains elusive. Here, we demonstrate a high-throughput, low-temperature, spatially controlled and scalable epitaxial graphene (EG) synthesis technique based on laser-induced surface decomposition of the Si-rich face of a SiC single-crystal. We confirm the formation of EG on SiC as a result of excimer laser irradiation by using reflection high-energy electron diffraction (RHEED), Raman spectroscopy, synchrotron-based X-ray diffraction, transmission electron microscopy (TEM), and scanning tunneling microscopy (STM). Laser fluence controls the thickness of the graphene film down to a single monolayer. Laser-synthesized graphene does not display some of the structural characteristics observed in EG grown by conventional thermal decomposition on SiC (0001), such as Bernal stacking and surface reconstruction of the underlying SiC surface.

  View details for DOI 10.1021/nn101796e

  View details for PubMedID 21121692

• TOPOLOGICAL INSULATORS A romance with many dimensions NATURE NANOTECHNOLOGY Manoharan, H. C. 2010; 5 (7): 477–79

  View details for DOI 10.1038/nnano.2010.138

  View details for Web of Science ID 000280529800003

  View details for PubMedID 20606637

• Detection and Cloaking of Molecular Objects in Coherent Nanostructures Using Inelastic Electron Tunneling Spectroscopy NANO LETTERS Fransson, J., Manoharan, H. C., Balatsky, A. V. 2010; 10 (5): 1600-1604

  Abstract

  We address quantum invisibility in the context of electronics in nanoscale quantum structures. We make use of the freedom of design that quantum corrals provide and show that quantum mechanical objects can be hidden inside the corral, with respect to inelastic electron scattering spectroscopy in combination with scanning tunneling microscopy, and we propose a design strategy. A simple illustration of the invisibility is given in terms of an elliptic quantum corral containing a molecule, with a local vibrational mode, at one of the foci. Our work has implications to quantum information technology and presents new tools for nonlocal quantum detection and distinguishing between different molecules.

  View details for DOI 10.1021/nl903991a

  View details for Web of Science ID 000277444900013

  View details for PubMedID 20402523

• Theory of Fano resonances in graphene: The influence of orbital and structural symmetries on STM spectra PHYSICAL REVIEW B Wehling, T. O., Dahal, H. P., Lichtenstein, A. I., Katsnelson, M. I., Manoharan, H. C., Balatsky, A. V. 2010; 81 (8)

  View details for DOI 10.1103/PhysRevB.81.085413

  View details for Web of Science ID 000275053300111

• Topological Insulator Nanowires and Nanoribbons NANO LETTERS Kong, D., Randel, J. C., Peng, H., Cha, J. J., Meister, S., Lai, K., Chen, Y., Shen, Z., Manoharan, H. C., Cui, Y. 2010; 10 (1): 329-333

  Abstract

  Recent theoretical calculations and photoemission spectroscopy measurements on the bulk Bi(2)Se(3) material show that it is a three-dimensional topological insulator possessing conductive surface states with nondegenerate spins, attractive for dissipationless electronics and spintronics applications. Nanoscale topological insulator materials have a large surface-to-volume ratio that can manifest the conductive surface states and are promising candidates for devices. Here we report the synthesis and characterization of high quality single crystalline Bi(2)Se(3) nanomaterials with a variety of morphologies. The synthesis of Bi(2)Se(3) nanowires and nanoribbons employs Au-catalyzed vapor-liquid-solid (VLS) mechanism. Nanowires, which exhibit rough surfaces, are formed by stacking nanoplatelets along the axial direction of the wires. Nanoribbons are grown along [1120] direction with a rectangular cross-section and have diverse morphologies, including quasi-one-dimensional, sheetlike, zigzag and sawtooth shapes. Scanning tunneling microscopy (STM) studies on nanoribbons show atomically smooth surfaces with approximately 1 nm step edges, indicating single Se-Bi-Se-Bi-Se quintuple layers. STM measurements reveal a honeycomb atomic lattice, suggesting that the STM tip couples not only to the top Se atomic layer, but also to the Bi atomic layer underneath, which opens up the possibility to investigate the contribution of different atomic orbitals to the topological surface states. Transport measurements of a single nanoribbon device (four terminal resistance and Hall resistance) show great promise for nanoribbons as candidates to study topological surface states.

  View details for DOI 10.1021/nl903663a

  View details for Web of Science ID 000273428700055

  View details for PubMedID 20030392

• Quantum holographic encoding in a two-dimensional electron gas NATURE NANOTECHNOLOGY Moon, C. R., Mattos, L. S., Foster, B. K., Zeltzer, G., Manoharan, H. C. 2009; 4 (3): 167-172

  Abstract

  The ability of the scanning tunnelling microscope to manipulate single atoms and molecules has allowed a single bit of information to be represented by a single atom or molecule. Although such information densities remain far beyond the reach of real-world devices, it has been assumed that the finite spacing between atoms in condensed-matter systems sets a rigid upper limit on information density. Here, we show that it is possible to exceed this limit with a holographic method that is based on electron wavefunctions rather than free-space optical waves. Scanning tunnelling microscopy and holograms comprised of individually manipulated molecules are used to create and detect electronically projected objects with features as small as approximately 0.3 nm, and to achieve information densities in excess of 20 bits nm-2. Our electronic quantum encoding scheme involves placing tens of bits of information into a single fermionic state.

  View details for DOI 10.1038/NNANO.2008.415

  View details for Web of Science ID 000264318500014

  View details for PubMedID 19265846

• Surface structure of cleaved (001) USb2 single crystal PHILOSOPHICAL MAGAZINE Chen, S. P., Hawley, M., Van Stockum, P. B., Manoharan, H. C., Bauer, E. D. 2009; 89 (22-24): 1881-1891

  View details for DOI 10.1080/14786430902785336

  View details for Web of Science ID 000268606800013

• Structure of Cleaved (001) USb2 Single Crystal Chen, S., Hawley, M., Van Stockum, P. B., Manoharan, H. C., Bauer, E. D., Moeck, P., Hovmoller, S., Nicolopoulos, S., Rouvimov, S., Petkov, Gateshki, M., Fraundorf, P. MATERIALS RESEARCH SOC. 2009: 163-+

  View details for Web of Science ID 000274190900019

• Single-atom gating of quantum-state superpositions NATURE PHYSICS Moon, C. R., Lutz, C. P., Manoharan, H. C. 2008; 4 (6): 454-458

  View details for DOI 10.1038/nphys930

  View details for Web of Science ID 000256613000011

• Quantum phase extraction in isospectral electronic nanostructures SCIENCE Moon, C. R., Mattos, L. S., Foster, B. K., Zeltzer, G., Ko, W., Manoharan, H. C. 2008; 319 (5864): 782-787

  Abstract

  Quantum phase is not directly observable and is usually determined by interferometric methods. We present a method to map complete electron wave functions, including internal quantum phase information, from measured single-state probability densities. We harness the mathematical discovery of drum-like manifolds bearing different shapes but identical resonances, and construct quantum isospectral nanostructures with matching electronic structure but divergent physical structure. Quantum measurement (scanning tunneling microscopy) of these "quantum drums"-degenerate two-dimensional electron states on the copper(111) surface confined by individually positioned carbon monoxide molecules-reveals that isospectrality provides an extra topological degree of freedom enabling robust quantum state transplantation and phase extraction.

  View details for DOI 10.1126/science.1151490

  View details for Web of Science ID 000252963000053

  View details for PubMedID 18258909

• Scanning optical homodyne detection of high-frequency picoscale resonances in cantilever and tuning fork sensors APPLIED PHYSICS LETTERS Zeltzer, G., Randel, J. C., Gupta, A. K., Bashir, R., Song, S., Manoharan, H. C. 2007; 91 (17)

  View details for DOI 10.1063/1.2803774

  View details for Web of Science ID 000250468200103

• Information transport and computation in nanometre-scale structures Meeting on Organizing Atoms Eigler, D. M., Lutz, C. P., Crommie, M. F., Manoharan, H. C., Heinrich, A. J., Gupta, J. A. ROYAL SOC. 2004: 1135–47

  Abstract

  We discuss two examples of novel information-transport and processing mechanisms in nanometre-scale structures. The local modulation and detection of a quantum state can be used for information transport at the nanometre length-scale, an effect we call a 'quantum mirage'. We demonstrate that, unlike conventional electronic information transport using wires, the quantum mirage can be used to pass multiple channels of information through the same volume of a solid. We discuss a new class of nanometre-scale structures called 'molecule cascades', and show how they may be used to implement a general-purpose binary-logic computer in which all of the circuitry is at the nanometre length-scale.

  View details for Web of Science ID 000222032900002

  View details for PubMedID 15306466

• Multiple interacting bilayer electron system: Magnetotransport and heat capacity measurements PHYSICAL REVIEW B Grivei, E., Melinte, S., Bayot, Manoharan, H. C., Shayegan, M. 2003; 68 (19)

  View details for DOI 10.1103/PhysRevB.68.193404

  View details for Web of Science ID 000187163000024

• Magnetism at the spatial limit 4th Conference on Physical Phenomena at High Magnetic Fields Manoharan, H. WORLD SCIENTIFIC PUBL CO PTE LTD. 2002: 3272–72

  View details for Web of Science ID 000178300100096

• Low-field magnetoresistance in GaAs two-dimensional holes PHYSICAL REVIEW B Papadakis, S. J., De Poortere, E. P., Manoharan, H. C., Yau, J. B., Shayegan, M., Lyon, S. A. 2002; 65 (24)

  View details for DOI 10.1103/PhysRevB.65.245312

  View details for Web of Science ID 000177043100071

• Applied physics - Spin spotting NATURE Manoharan, H. C. 2002; 416 (6876): 24–25

  View details for DOI 10.1038/416024a

  View details for Web of Science ID 000174211600021

  View details for PubMedID 11882873

• Scattering theory of Kondo mirages and observation of single Kondo atom phase shift PHYSICAL REVIEW LETTERS Fiete, G. A., Hersch, J. S., Heller, E. J., Manoharan, H. C., Lutz, C. P., Eigler, D. M. 2001; 86 (11): 2392–95

  Abstract

  We explain the origin of the Kondo mirage seen in recent quantum corral scanning tunneling microscope experiments with a scattering theory of electrons on the surfaces of metals. Our theory, combined with experimental data, provides a direct observation of a single Kondo atom phase shift. The Kondo mirage observed at the empty focus of an elliptical quantum corral is shown to arise from multiple electron bounces off the corral wall adatoms. We demonstrate our theory with direct quantitive comparison to experimental data.

  View details for PubMedID 11289937

• Quantum mirages formed by coherent projection of electronic structure NATURE Manoharan, H. C., Lutz, C. P., Eigler, D. M. 2000; 403 (6769): 512–15

  View details for DOI 10.1038/35000508

  View details for Web of Science ID 000085227300040

• Quantum mirages formed by coherent projection of electronic structure Nature Manoharan, H. C., Lutz, C. P., Eigler, D. M. 2000; 403 (6769): 512-5

  Abstract

  Image projection relies on classical wave mechanics and the use of natural or engineered structures such as lenses or resonant cavities. Well-known examples include the bending of light to create mirages in the atmosphere, and the focusing of sound by whispering galleries. However, the observation of analogous phenomena in condensed matter systems is a more recent development, facilitated by advances in nanofabrication. Here we report the projection of the electronic structure surrounding a magnetic Co atom to a remote location on the surface of a Cu crystal; electron partial waves scattered from the real Co atom are coherently refocused to form a spectral image or 'quantum mirage'. The focusing device is an elliptical quantum corral, assembled on the Cu surface. The corral acts as a quantum mechanical resonator, while the two-dimensional Cu surface-state electrons form the projection medium. When placed on the surface, Co atoms display a distinctive spectroscopic signature, known as the many-particle Kondo resonance, which arises from their magnetic moment. By positioning a Co atom at one focus of the ellipse, we detect a strong Kondo signature not only at the atom, but also at the empty focus. This behaviour contrasts with the usual spatially-decreasing response of an electron gas to a localized perturbation.

  View details for DOI 10.1038/35000508

  View details for PubMedID 10676952

• Tunable B=0 spin-splitting and its effect on the metallic behavior of GaAs two-dimensional holes PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES Papadakis, S. J., De Poortere, E. P., Manoharan, H. C., Shayegan, M., Winkler, R. 2000; 6 (1-4): 284–87

  View details for DOI 10.1016/S1386-9477(99)00155-1

  View details for Web of Science ID 000085770600069

• Anisotropic transport of two-dimensional holes in high Landau levels PHYSICA E Shayegan, M., Manoharan, H. C., Papadakis, S. J., De Poortere, E. P. 2000; 6 (1-4): 40–42

  View details for DOI 10.1016/S1386-9477(99)00056-9

  View details for Web of Science ID 000085770600010

• Highly anisotropic commensurability oscillations in two-dimensional holes at the GaAs/AlGaAs (311)A interface PHYSICA E Yau, J. B., Lu, J. P., Manoharan, H. C., Shayegan, M. 2000; 6 (1-4): 453–56

  View details for DOI 10.1016/S1386-9477(99)00209-X

  View details for Web of Science ID 000085770600107

• The effect of spin splitting on the metallic behavior of a two-dimensional system SCIENCE Papadakis, S. J., De Poortere, E. P., Manoharan, H. C., Shayegan, M., Winkler, R. 1999; 283 (5410): 2056–58

  View details for DOI 10.1126/science.283.5410.2056

  View details for Web of Science ID 000079369800037

• The effect of spin splitting on the metallic behavior of a two-dimensional system Science (New York, N.Y.) Papadakis, S. J., Manoharan, H. C., Shayegan, M., Winkler, R. 1999; 283 (5410): 2056-8

  Abstract

  Experiments on a constant-density two-dimensional hole system in a gallium arsenide quantum well revealed that the metallic behavior observed in the zero-magnetic-field temperature dependence of the resistivity depends on the symmetry of the confinement potential and the resulting spin splitting of the valence band.

  View details for PubMedID 10092222

• Macroscopic correlation-driven charge transfer between capacitively isolated electron layers Manoharan, H. C., Suen, Y. W., Lay, T. S., Santos, M. B., Shayegan, M. ELSEVIER SCIENCE BV. 1998: 814–18

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  View details for Web of Science ID 000074919400176

• Interaction-induced interlayer charge transfer at high magnetic fields Manoharan, H. C., Suen, Y. W., Lay, T. S., Santos, M. B., Shayegan, M. ELSEVIER SCIENCE BV. 1997: 172–75

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  View details for Web of Science ID 000074364500037

• Spontaneous interlayer charge transfer near the magnetic quantum limit PHYSICAL REVIEW LETTERS Manoharan, H. C., Suen, Y. W., Lay, T. S., Santos, M. B., Shayegan, M. 1997; 79 (14): 2722–25

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  View details for Web of Science ID A1997XZ54400031

• Correlated bilayer electron states Shayegan, M., Manoharan, H. C., Suen, Y. W., Lay, T. S., Santos, M. B. IOP PUBLISHING LTD. 1996: 1539–45

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  View details for Web of Science ID A1996VW13000015

• Evidence for a bilayer quantum Wigner solid PHYSICAL REVIEW LETTERS Manoharan, H. C., Suen, Y. W., Santos, M. B., Shayegan, M. 1996; 77 (9): 1813–16

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  View details for Web of Science ID A1996VD43000039

• Correlated insulating states of an interacting bilayer electron system Manoharan, H. C., Suen, Y. W., Santos, M. B., Shayegan, M. ELSEVIER SCIENCE BV. 1996: 106–12

  View details for DOI 10.1016/0039-6028(96)00343-3

  View details for Web of Science ID A1996UZ03300028

• CHARGE-TRANSFER AT DOUBLE-LAYER TO SINGLE-LAYER TRANSITION IN DOUBLE-QUANTUM-WELL SYSTEMS PHYSICAL REVIEW B KATAYAMA, Y., TSUI, D. C., MANOHARAN, H. C., PARIHAR, S., SHAYEGAN, M. 1995; 52 (20): 14817–24

  View details for DOI 10.1103/PhysRevB.52.14817

  View details for Web of Science ID A1995TH68200076

• TIME-RESOLVED PHOTOLUMINESCENCE OF A 2-DIMENSIONAL HOLE SYSTEM IN THE EXTREME QUANTUM LIMIT PHYSICAL REVIEW B KULIK, L. V., DOLGOPOLOV, V. T., SHASHKIN, A. A., DITE, A. F., BUTOV, L. V., KULAKOVSKII, V. D., MANOHARAN, H. C., SHAYEGAN, M. 1995; 51 (19): 13876–79

  View details for DOI 10.1103/PhysRevB.51.13876

  View details for Web of Science ID A1995QZ16500124

• WIGNER CRYSTAL VERSUS HALL INSULATOR PHYSICAL REVIEW B MANOHARAN, H. C., SHAYEGAN, M. 1994; 50 (23): 17662–65

  View details for DOI 10.1103/PhysRevB.50.17662

  View details for Web of Science ID A1994PZ82500111

• ANOMALOUS TEMPERATURE-DEPENDENCE OF THE CORRELATED NU=1 QUANTUM HALL-EFFECT IN BILAYER ELECTRON-SYSTEMS PHYSICAL REVIEW B LAY, T. S., SUEN, Y. W., MANOHARAN, H. C., YING, SANTOS, M. B., SHAYEGAN, M. 1994; 50 (23): 17725–28

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  View details for Web of Science ID A1994PZ82500127

• SIGNATURES OF A NOVEL FERMI-LIQUID IN A 2-DIMENSIONAL COMPOSITE PARTICLE METAL PHYSICAL REVIEW LETTERS MANOHARAN, H. C., SHAYEGAN, M., KLEPPER, S. J. 1994; 73 (24): 3270–73

  View details for DOI 10.1103/PhysRevLett.73.3270

  View details for Web of Science ID A1994PW97800023

• ORIGIN OF THE V = 1/2 FRACTIONAL QUANTUM HALL STATE IN WIDE SINGLE QUANTUM-WELLS PHYSICAL REVIEW LETTERS SUEN, Y. W., MANOHARAN, H. C., YING, SANTOS, M. B., SHAYEGAN, M. 1994; 72 (21): 3405–8

  View details for DOI 10.1103/PhysRevLett.72.3405

  View details for Web of Science ID A1994NM83500030

• MAGNETOOPTICS OF 2-DIMENSIONAL HOLE SYSTEMS IN THE EXTREME QUANTUM LIMIT PHYSICAL REVIEW B BUTOV, L. V., ZRENNER, A., SHAYEGAN, M., ABSTREITER, G., MANOHARAN, H. C. 1994; 49 (19): 14054–57

  View details for DOI 10.1103/PhysRevB.49.14054

  View details for Web of Science ID A1994NN99300102

• ONE-COMPONENT TO 2-COMPONENT TRANSITIONS OF FRACTIONAL QUANTUM HALL STATES IN A WIDE QUANTUM-WELL SUEN, Y. W., MANOHARAN, H. C., YING, SANTOS, M. B., SHAYEGAN, M. ELSEVIER SCIENCE BV. 1994: 13–17

  View details for DOI 10.1016/0039-6028(94)90852-4

  View details for Web of Science ID A1994ND67400003

• OBSERVATION OF AN ABRUPT DOUBLE-TO-SINGLE-LAYER TRANSITION IN A DOUBLE-QUANTUM-WELL STRUCTURE KATAYAMA, Y., TSUI, D. C., MANOHARAN, H. C., SHAYEGAN, M. ELSEVIER SCIENCE BV. 1994: 405–7

  View details for DOI 10.1016/0039-6028(94)90926-1

  View details for Web of Science ID A1994ND67400077

• SURFACE RESONANT-TUNNELING TRANSISTOR - A NEW NEGATIVE TRANSCONDUCTANCE DEVICE APPLIED PHYSICS LETTERS KURDAK, C., TSUI, D. C., PARIHAR, S., SANTOS, M. B., MANOHARAN, H. C., LYON, S. A., SHAYEGAN, M. 1994; 64 (5): 610–12

  View details for DOI 10.1063/1.111065

  View details for Web of Science ID A1994MU63300027

• A NEW RESONANT-TUNNELING TRANSISTOR FABRICATED BY CLEAVED EDGE OVERGROWTH KURDAK, C., TSUI, D. C., PARIHAR, S., MANOHARAN, H., LYON, S. A., SHAYEGAN, M., IEEE I E E E. 1993: 265–69

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• HIGH-LIFETIME STRAINED SI1-XGEX FILMS GROWN BY RAPID THERMAL CHEMICAL VAPOR-DEPOSITION STURM, J. C., SCHWARTZ, P. V., MANOHARAN, H., XIAO, MI, Q. ELSEVIER SCIENCE SA LAUSANNE. 1992: 29–32

  View details for DOI 10.1016/0924-4247(92)80220-W

  View details for Web of Science ID A1992HZ81700006

• OPTICAL-PROPERTIES OF SI1-XGEX QUANTUM-WELLS AND SUPERLATTICES GROWN BY RAPID THERMAL CHEMICAL VAPOR-DEPOSITION STURM, J. C., XIAO, MANOHARAN, H., SCHWARTZ, P. V., MOSLEHI, M. M., SINGH, R., KWONG, D. L. SPIE - INT SOC OPTICAL ENGINEERING. 1992: 90–98

  View details for DOI 10.1117/12.56667

  View details for Web of Science ID A1992BV45H00010

• GROWTH OF SI1-XGEX BY RAPID THERMAL CHEMICAL VAPOR-DEPOSITION AND APPLICATION TO HETEROJUNCTION BIPOLAR-TRANSISTORS JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B STURM, J. C., SCHWARTZ, P. V., PRINZ, E. J., MANOHARAN, H. 1991; 9 (4): 2011–16

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  View details for Web of Science ID A1991GB89700018

• WELL-RESOLVED BAND-EDGE PHOTOLUMINESCENCE OF EXCITONS CONFINED IN STRAINED SI1-XGEX QUANTUM-WELLS PHYSICAL REVIEW LETTERS STURM, J. C., MANOHARAN, H., LENCHYSHYN, L. C., THEWALT, M. L., ROWELL, N. L., NOEL, J. P., HOUGHTON, D. C. 1991; 66 (10): 1362–65

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  View details for Web of Science ID A1991FA69200029