I am a theoretical condensed matter physicist. My general research interests lie in exploring all the exotic states of matter that can arise in quantum systems.

I am currently interested in studying topological states that can arise in a class of 2D quantum materials known as moiré materials.

I did my bachelor's at Northeastern, a PhD at Princeton, and a postdoc at MIT, before joining Stanford as an assistant professor. I grew up in Bangkok, Thailand.

Academic Appointments

Professional Education

  • PhD, Princeton University, Physics (2021)
  • BSc, Northeastern University, Physics (2015)

2023-24 Courses

Stanford Advisees

All Publications

  • Artificial Atoms, Wigner Molecules, and an Emergent Kagome Lattice in Semiconductor Moiré Superlattices. Physical review letters Reddy, A. P., Devakul, T., Fu, L. 2023; 131 (24): 246501


    Semiconductor moiré superlattices comprise an array of artificial atoms and provide a highly tunable platform for exploring novel electronic phases. We introduce a theoretical framework for studying moiré quantum matter that treats intra-moiré-atom interactions exactly and is controlled in the limit of large moiré period. We reveal an abundance of new physics arising from strong electron interactions when there are multiple electrons within a moiré unit cell. In particular, at filling factor n=3, the Coulomb interaction within each three-electron moiré atom leads to a three-lobed "Wigner molecule." When their size is comparable to the moiré period, the Wigner molecules form an emergent Kagome lattice. Our Letter identifies two universal length scales characterizing the kinetic and interaction energies in moiré materials and demonstrates a rich phase diagram due to their interplay.

    View details for DOI 10.1103/PhysRevLett.131.246501

    View details for PubMedID 38181155

  • Hofstadter states and re-entrant charge order in a semiconductor moire lattice NATURE PHYSICS Kometter, C. R., Yu, J., Devakul, T., Reddy, A. P., Zhang, Y., Foutty, B. A., Watanabe, K., Taniguchi, T., Fu, L., Feldman, B. E. 2023; 19 (12): 1861-+
  • Magic-angle helical trilayer graphene. Science advances Devakul, T., Ledwith, P. J., Xia, L. Q., Uri, A., de la Barrera, S. C., Jarillo-Herrero, P., Fu, L. 2023; 9 (36): eadi6063


    We propose magic-angle helical trilayer graphene (HTG), a helical structure featuring identical rotation angles between three consecutive layers of graphene, as a unique and experimentally accessible platform for realizing exotic correlated topological states of matter. While nominally forming a supermoiré (or moiré-of-moiré) structure, we show that HTG locally relaxes into large regions of a periodic single-moiré structure realizing flat topological bands carrying nontrivial valley Chern number. These bands feature near-ideal quantum geometry and are isolated from remote bands by a very large energy gap, making HTG a promising platform for experimental realization of correlated topological states such as integer and fractional quantum anomalous Hall states.

    View details for DOI 10.1126/sciadv.adi6063

    View details for PubMedID 37672575

    View details for PubMedCentralID PMC10482339

  • Superconductivity and strong interactions in a tunable moiré quasicrystal. Nature Uri, A., de la Barrera, S. C., Randeria, M. T., Rodan-Legrain, D., Devakul, T., Crowley, P. J., Paul, N., Watanabe, K., Taniguchi, T., Lifshitz, R., Fu, L., Ashoori, R. C., Jarillo-Herrero, P. 2023; 620 (7975): 762-767


    Electronic states in quasicrystals generally preclude a Bloch description1, rendering them fascinating and enigmatic. Owing to their complexity and scarcity, quasicrystals are underexplored relative to periodic and amorphous structures. Here we introduce a new type of highly tunable quasicrystal easily assembled from periodic components. By twisting three layers of graphene with two different twist angles, we form two mutually incommensurate moiré patterns. In contrast to many common atomic-scale quasicrystals2,3, the quasiperiodicity in our system is defined on moiré length scales of several nanometres. This 'moiré quasicrystal' allows us to tune the chemical potential and thus the electronic system between a periodic-like regime at low energies and a strongly quasiperiodic regime at higher energies, the latter hosting a large density of weakly dispersing states. Notably, in the quasiperiodic regime, we observe superconductivity near a flavour-symmetry-breaking phase transition4,5, the latter indicative of the important role that electronic interactions play in that regime. The prevalence of interacting phenomena in future systems with in situ tunability is not only useful for the study of quasiperiodic systems but may also provide insights into electronic ordering in related periodic moiré crystals6-12. We anticipate that extending this platform to engineer quasicrystals by varying the number of layers and twist angles, and by using different two-dimensional components, will lead to a new family of quantum materials to investigate the properties of strongly interacting quasicrystals.

    View details for DOI 10.1038/s41586-023-06294-z

    View details for PubMedID 37468640

    View details for PubMedCentralID 8364166

  • Tunable spin and valley excitations of correlated insulators in Γ-valley moiré bands. Nature materials Foutty, B. A., Yu, J., Devakul, T., Kometter, C. R., Zhang, Y., Watanabe, K., Taniguchi, T., Fu, L., Feldman, B. E. 2023


    Moiré superlattices formed from transition metal dichalcogenides support a variety of quantum electronic phases that are highly tunable using applied electromagnetic fields. While the valley degree of freedom affects optoelectronic properties in the constituent transition metal dichalcogenides, it has yet to be fully explored in moiré systems. Here we establish twisted double-bilayer WSe2 as an experimental platform to study electronic correlations within Γ-valley moiré bands. Through local and global electronic compressibility measurements, we identify charge-ordered phases at multiple integer and fractional moiré fillings. By measuring the magnetic field dependence of their energy gaps and the chemical potential upon doping, we reveal spin-polarized ground states with spin-polaron quasiparticle excitations. In addition, an applied displacement field induces a metal-insulator transition driven by tuning between Γ- and K-valley moiré bands. Our results demonstrate control over the spin and valley character of the correlated ground and excited states in this system.

    View details for DOI 10.1038/s41563-023-01534-z

    View details for PubMedID 37069292

  • Moiré Landau Fans and Magic Zeros. Physical review letters Paul, N., Crowley, P. J., Devakul, T., Fu, L. 2022; 129 (11): 116804


    We study the energy spectrum of moiré systems under a uniform magnetic field. The superlattice potential generally broadens Landau levels into Chern bands with finite bandwidth. However, we find that these Chern bands become flat at a discrete set of magnetic fields which we dub "magic zeros." The flat band subspace is generally different from the Landau level subspace in the absence of the moiré superlattice. By developing a semiclassical quantization method and taking account of superlattice induced Bragg reflection, we prove that magic zeros arise from the simultaneous quantization of two distinct k-space orbits. For instance, we show the chiral model of TBG has flat bands at special fields for any twist angle in the nth Landau level for |n|>1. The flat bands at magic zeros provide a new setting for exploring crystalline fractional quantum Hall physics.

    View details for DOI 10.1103/PhysRevLett.129.116804

    View details for PubMedID 36154430

  • Anomaly inflow for subsystem symmetries PHYSICAL REVIEW B Burnell, F. J., Devakul, T., Gorantla, P., Lam, H., Shao, S. 2022; 106 (8)
  • Quantum Anomalous Hall Effect from Inverted Charge Transfer Gap PHYSICAL REVIEW X Devakul, T., Fu, L. 2022; 12 (2)
  • One-dimensional Luttinger liquids in a two-dimensional moire lattice NATURE Wang, P., Yu, G., Kwan, Y. H., Jia, Y., Lei, S., Klemenz, S., Cevallos, F., Singha, R., Devakul, T., Watanabe, K., Taniguchi, T., Sondhi, S. L., Cava, R. J., Schoop, L. M., Parameswaran, S. A., Wu, S. 2022; 605 (7908): 57-+


    The Luttinger liquid (LL) model of one-dimensional (1D) electronic systems provides a powerful tool for understanding strongly correlated physics, including phenomena such as spin-charge separation1. Substantial theoretical efforts have attempted to extend the LL phenomenology to two dimensions, especially in models of closely packed arrays of 1D quantum wires2-13, each being described as a LL. Such coupled-wire models have been successfully used to construct two-dimensional (2D) anisotropic non-Fermi liquids2-6, quantum Hall states7-9, topological phases10,11 and quantum spin liquids12,13. However, an experimental demonstration of high-quality arrays of 1D LLs suitable for realizing these models remains absent. Here we report the experimental realization of 2D arrays of 1D LLs with crystalline quality in a moiré superlattice made of twisted bilayer tungsten ditelluride (tWTe2). Originating from the anisotropic lattice of the monolayer, the moiré pattern of tWTe2 hosts identical, parallel 1D electronic channels, separated by a fixed nanoscale distance, which is tuneable by the interlayer twist angle. At a twist angle of approximately 5 degrees, we find that hole-doped tWTe2 exhibits exceptionally large transport anisotropy with a resistance ratio of around 1,000 between two orthogonal in-plane directions. The across-wire conductance exhibits power-law scaling behaviours, consistent with the formation of a 2D anisotropic phase that resembles an array of LLs. Our results open the door for realizing a variety of correlated and topological quantum phases based on coupled-wire models and LL physics.

    View details for DOI 10.1038/s41586-022-04514-6

    View details for Web of Science ID 000790960500014

    View details for PubMedID 35508779

    View details for PubMedCentralID 7048812

  • Quantum anomalous Hall effect from intertwined moiré bands. Nature Li, T., Jiang, S., Shen, B., Zhang, Y., Li, L., Tao, Z., Devakul, T., Watanabe, K., Taniguchi, T., Fu, L., Shan, J., Mak, K. F. 2021; 600 (7890): 641-646


    Electron correlation and topology are two central threads of modern condensed matter physics. Semiconductor moiré materials provide a highly tuneable platform for studies of electron correlation1-12. Correlation-driven phenomena, including the Mott insulator2-5, generalized Wigner crystals2,6,9, stripe phases10 and continuous Mott transition11,12, have been demonstrated. However, non-trivial band topology has remained unclear. Here we report the observation of a quantum anomalous Hall effect in AB-stacked MoTe2 /WSe2 moiré heterobilayers. Unlike in the AA-stacked heterobilayers11, an out-of-plane electric field not only controls the bandwidth but also the band topology by intertwining moiré bands centred at different layers. At half band filling, corresponding to one particle per moiré unit cell, we observe quantized Hall resistance, h/e2 (with h and e denoting the Planck's constant and electron charge, respectively), and vanishing longitudinal resistance at zero magnetic field. The electric-field-induced topological phase transition from a Mott insulator to a quantum anomalous Hall insulator precedes an insulator-to-metal transition. Contrary to most known topological phase transitions13, it is not accompanied by a bulk charge gap closure. Our study paves the way for discovery of emergent phenomena arising from the combined influence of strong correlation and topology in semiconductor moiré materials.

    View details for DOI 10.1038/s41586-021-04171-1

    View details for PubMedID 34937897

    View details for PubMedCentralID 8433558

  • Magic in twisted transition metal dichalcogenide bilayers NATURE COMMUNICATIONS Devakul, T., Crepel, V., Zhang, Y., Fu, L. 2021; 12 (1): 6730


    The long-wavelength moiré superlattices in twisted 2D structures have emerged as a highly tunable platform for strongly correlated electron physics. We study the moiré bands in twisted transition metal dichalcogenide homobilayers, focusing on WSe2, at small twist angles using a combination of first principles density functional theory, continuum modeling, and Hartree-Fock approximation. We reveal the rich physics at small twist angles θ < 4∘, and identify a particular magic angle at which the top valence moiré band achieves almost perfect flatness. In the vicinity of this magic angle, we predict the realization of a generalized Kane-Mele model with a topological flat band, interaction-driven Haldane insulator, and Mott insulators at the filling of one hole per moiré unit cell. The combination of flat dispersion and uniformity of Berry curvature near the magic angle holds promise for realizing fractional quantum anomalous Hall effect at fractional filling. We also identify twist angles favorable for quantum spin Hall insulators and interaction-induced quantum anomalous Hall insulators at other integer fillings.

    View details for DOI 10.1038/s41467-021-27042-9

    View details for Web of Science ID 000720682300053

    View details for PubMedID 34795273

    View details for PubMedCentralID PMC8602625

  • Theory of competing excitonic orders in insulating WTe2 monolayers PHYSICAL REVIEW B Kwan, Y. H., Devakul, T., Sondhi, S. L., Parameswaran, S. A. 2021; 104 (12)
  • Quantum Oscillations in the Zeroth Landau Level: Serpentine Landau Fan and the Chiral Anomaly PHYSICAL REVIEW LETTERS Devakul, T., Kwan, Y. H., Sondhi, S. L., Parameswaran, S. A. 2021; 127 (11): 116602


    We identify an unusual mechanism for quantum oscillations in nodal semimetals, driven by a single pair of Landau levels periodically closing their gap at the Fermi energy as a magnetic field is varied. These "zero Landau level" quantum oscillations (ZQOs) appear in the nodal limit where the zero-field Fermi volume vanishes and have distinctive periodicity and temperature dependence. We link the Landau spectrum of a two-dimensional (2D) nodal semimetal to the Rabi model, and show by exact solution that, across the entire Landau fan, pairs of opposite-parity Landau levels are intertwined in a "serpentine" manner. We propose 2D surfaces of topological crystalline insulators as natural settings for ZQOs. In certain 3D nodal semimetals, ZQOs lead to oscillations of anomaly physics. We propose a transport measurement capable of observing such oscillations, which we demonstrate numerically.

    View details for DOI 10.1103/PhysRevLett.127.116602

    View details for Web of Science ID 000704656200011

    View details for PubMedID 34558955

  • Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers. Proceedings of the National Academy of Sciences of the United States of America Zhang, Y., Devakul, T., Fu, L. 2021; 118 (36)


    While transition-metal dichalcogenide (TMD)-based moiré materials have been shown to host various correlated electronic phenomena, topological states have not been experimentally observed until now [T. Li et al., Quantum anomalous Hall effect from intertwined moiré bands. arXiv [Preprint] (2021). (Accessed 5 July 2021)]. In this work, using first-principle calculations and continuum modeling, we reveal the displacement field-induced topological moiré bands in AB-stacked TMD heterobilayer [Formula: see text]/[Formula: see text] Valley-contrasting Chern bands with nontrivial spin texture are formed from interlayer hybridization between [Formula: see text] and [Formula: see text] bands of nominally opposite spins. Our study establishes a recipe for creating topological bands in AB-stacked TMD bilayers in general, which provides a highly tunable platform for realizing quantum-spin Hall and interaction-induced quantum anomalous Hall effects.

    View details for DOI 10.1073/pnas.2112673118

    View details for PubMedID 34475221

    View details for PubMedCentralID PMC8433558

  • Fractalizing quantum codes QUANTUM Devakul, T., Williamson, D. J. 2021; 5
  • Type-II fractons from coupled spin chains and layers PHYSICAL REVIEW B Williamson, D. J., Devakul, T. 2021; 103 (15)
  • Floating topological phases PHYSICAL REVIEW B Devakul, T., Sondhi, S. L., Kivelson, S. A., Berg, E. 2020; 102 (12)
  • Fractonic Chern-Simons and BF theories PHYSICAL REVIEW RESEARCH You, Y., Devakul, T., Sondhi, S. L., Burnell, F. J. 2020; 2 (2)
  • Symmetric fracton matter: Twisted and enriched ANNALS OF PHYSICS You, Y., Devakul, T., Burnell, F. J., Sondhi, S. L. 2020; 416
  • Strong planar subsystem symmetry-protected topological phases and their dual fracton orders PHYSICAL REVIEW RESEARCH Devakul, T., Shirley, W., Wang, J. 2020; 2 (1)
  • Extension of the eigenstate thermalization hypothesis to nonequilibrium steady states PHYSICAL REVIEW B Moudgalya, S., Devakul, T., Arovas, D. P., Sondhi, S. L. 2019; 100 (4)
  • Classifying local fractal subsystem symmetry-protected topological phases PHYSICAL REVIEW B Devakul, T. 2019; 99 (23)
  • Operator spreading in quantum maps PHYSICAL REVIEW B Moudgalya, S., Devakul, T., von Keyserlingk, C. W., Sondhi, S. L. 2019; 99 (9)
  • Fractal symmetric phases of matter SCIPOST PHYSICS Devakul, T., You, Y., Burnell, F. J., Sondhi, S. L. 2019; 6 (1)
  • Classification of subsystem symmetry-protected topological phases PHYSICAL REVIEW B Devakul, T., Williamson, D. J., You, Y. 2018; 98 (23)
  • Higher-order symmetry-protected topological states for interacting bosons and fermions PHYSICAL REVIEW B You, Y., Devakul, T., Burnell, F. J., Neupert, T. 2018; 98 (23)
  • Universal quantum computation using fractal symmetry-protected cluster phases PHYSICAL REVIEW A Devakul, T., Williamson, D. J. 2018; 98 (2)
  • Subsystem symmetry protected topological order PHYSICAL REVIEW B You, Y., Devakul, T., Burnell, F. J., Sondhi, S. L. 2018; 98 (3)
  • Probing the Quench Dynamics of Antiferromagnetic Correlations in a 2D Quantum Ising Spin System PHYSICAL REVIEW X Guardado-Sanchez, E., Brown, P. T., Mitra, D., Devakul, T., Huse, D. A., Schauss, P., Bakr, W. S. 2018; 8 (2)
  • Z(3) topological order in the face-centered-cubic quantum plaquette model PHYSICAL REVIEW B Devakul, T. 2018; 97 (15)
  • Quantum gas microscopy of an attractive Fermi-Hubbard system NATURE PHYSICS Mitra, D., Brown, P. T., Guardado-Sanchez, E., Kondov, S. S., Devakul, T., Huse, D. A., Schauss, P., Bakr, W. S. 2018; 14 (2): 173-+

    View details for DOI 10.1038/NPHYS4297

    View details for Web of Science ID 000423846600026

  • Entanglement of purification: from spin chains to holography JOURNAL OF HIGH ENERGY PHYSICS Phuc Nguyen, Devakul, T., Halbasch, M. G., Zaletel, M. P., Swingle, B. 2018
  • Correlation function diagnostics for type-I fracton phases PHYSICAL REVIEW B Devakul, T., Parameswaran, S. A., Sondhi, S. L. 2018; 97 (4)
  • Obtaining highly excited eigenstates of the localized XX chain via DMRG-X PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES Devakul, T., Khemani, V., Pollmann, F., Huse, D. A., Sondhi, S. L. 2017; 375 (2108)


    We benchmark a variant of the recently introduced density matrix renormalization group (DMRG)-X algorithm against exact results for the localized random field XX chain. We find that the eigenstates obtained via DMRG-X exhibit a highly accurate l-bit description for system sizes much bigger than the direct, many-body, exact diagonalization in the spin variables is able to access. We take advantage of the underlying free fermion description of the XX model to accurately test the strengths and limitations of this algorithm for large system sizes. We discuss the theoretical constraints on the performance of the algorithm from the entanglement properties of the eigenstates, and its actual performance at different values of disorder. A small but significant improvement to the algorithm is also presented, which helps significantly with convergence. We find that, at high entanglement, DMRG-X shows a bias towards eigenstates with low entanglement, but can be improved with increased bond dimension. This result suggests that one must be careful when applying the algorithm for interacting many-body localized spin models near a transition.This article is part of the themed issue 'Breakdown of ergodicity in quantum systems: from solids to synthetic matter'.

    View details for DOI 10.1098/rsta.2016.0431

    View details for Web of Science ID 000413927000006

    View details for PubMedID 29084883

    View details for PubMedCentralID PMC5665784

  • Anderson localization transitions with and without random potentials PHYSICAL REVIEW B Devakul, T., Huse, D. A. 2017; 96 (21)
  • Probability distribution of the entanglement across a cut at an infinite-randomness fixed point PHYSICAL REVIEW B Devakul, T., Majumdar, S. N., Huse, D. A. 2017; 95 (10)
  • Many-body localization phase transition: A simplified strong-randomness approximate renormalization group PHYSICAL REVIEW B Zhang, L., Zhao, B., Devakul, T., Huse, D. A. 2016; 93 (22)
  • Nonzero-temperature entanglement negativity of quantum spin models: Area law, linked cluster expansions, and sudden death PHYSICAL REVIEW E Sherman, N. E., Devakul, T., Hastings, M. B., Singh, R. P. 2016; 93 (2): 022128


    We show that the bipartite logarithmic entanglement negativity (EN) of quantum spin models obeys an area law at all nonzero temperatures. We develop numerical linked cluster (NLC) expansions for the "area-law" logarithmic entanglement negativity as a function of temperature and other parameters. For one-dimensional models the results of NLC are compared with exact diagonalization on finite systems and are found to agree very well. The NLC results are also obtained for two dimensional XXZ and transverse field Ising models. In all cases, we find a sudden onset (or sudden death) of negativity at a finite temperature above which the negativity is zero. We use perturbation theory to develop a physical picture for this sudden onset (or sudden death). The onset of EN or its magnitude are insensitive to classical finite-temperature phase transitions, supporting the argument for absence of any role of quantum mechanics at such transitions. On approach to a quantum critical point at T=0, negativity shows critical scaling in size and temperature.

    View details for DOI 10.1103/PhysRevE.93.022128

    View details for Web of Science ID 000370619600004

    View details for PubMedID 26986309

  • Unusual corrections to scaling and convergence of universal Renyi properties at quantum critical points PHYSICAL REVIEW B Sahoo, S., Stoudenmire, E., Stephan, J., Devakul, T., Singh, R. P., Melko, R. G. 2016; 93 (8)
  • Early Breakdown of Area-Law Entanglement at the Many-Body Delocalization Transition PHYSICAL REVIEW LETTERS Devakul, T., Singh, R. P. 2015; 115 (18): 187201


    We introduce the numerical linked cluster expansion as a controlled numerical tool for the study of the many-body localization transition in a disordered system with continuous nonperturbative disorder. Our approach works directly in the thermodynamic limit, in any spatial dimension, and does not rely on any finite size scaling procedure. We study the onset of many-body delocalization through the breakdown of area-law entanglement in a generic many-body eigenstate. By looking for initial signs of an instability of the localized phase, we obtain a value for the critical disorder, which we believe should be a lower bound for the true value, that is higher than current best estimates from finite size studies. This implies that most current methods tend to overestimate the extent of the localized phase due to finite size effects making the localized phase appear stable at small length scales. We also study the mobility edge in these systems as a function of energy density, and we find that our conclusion is the same at all examined energies.

    View details for DOI 10.1103/PhysRevLett.115.187201

    View details for Web of Science ID 000363507300009

    View details for PubMedID 26565492