I am a Nano- and Quantum Science and Engineering Postdoctoral Fellow working with the Nanoscale and Quantum Photonics Lab at Stanford University. My research interests involve quantum optics, quantum electrodynamics, color center systems and scalable solid-state photonics. In my graduate work, I explored silicon carbide and color center quantum photonics through modeling, nanofabrication and confocal photoluminescence under the supervision of Prof. Jelena Vučković at Stanford University. I hold a Ph.D. in applied physics and undergraduate degrees in physics and computer science. In past, I have done research at Hewlett-Packard Laboratories, Lawrence Berkeley National Lab, Oxford University, Austrian Academy of Science, Polish Academy of Science, Helmholtz Center Berlin and Belgrade Institute of Physics.
I am passionate about science education. As an officer in the Stanford Optical Society and the Board of European Students of Technology, I organized teams that provided educational opportunities to thousands of K-12 and hundreds od university level students. For more information about my research and education involvement please visit www.radulaski.com.
Honors & Awards
Nano- and Quantum Science and Engineering Postdoctoral Fellowship, Stanford University (2017-2019)
Honorary Speaker at the Stanford University Applied Physics and Physics Commencement, Stanford University (2016)
Best Student Presentation at the OSA Nonlinear Optics Conference, OSA Optical Society (2015)
Stanford Graduate Fellowship, Gabilan Fellow, Stanford University (2012-2014)
30 Under 30 Up-And-Coming Physicists, Scientific American (2012)
Prof. Dr. Ljubomir Cirkovic award for the best undergraduate thesis in physics, University of Belgrade (2011)
Boards, Advisory Committees, Professional Organizations
Quantum Optics of Atoms, Molecules and Solids Committee member, CLEO 2018 conference (2017 - Present)
Co-President, Stanford Optical Society (2014 - 2015)
Women in Photonics event organizer, Stanford Photonics Research Center (2014 - 2015)
Stanford University Photonics Retreat organizer, Stanford Optical Society (2012 - 2016)
Outreach Committee Co-Chair, Stanford Optical Society (2012 - 2014)
Executive board member for Belgrade local group, Board of European Students of Technology (2007 - 2008)
Doctor of Philosophy, Stanford University, APLPH-PHD (2017)
Bachelor of Science, University of Belgrade, Theoretical Physics (2011)
Diploma, Union University School of Computing (2009)
Current Research and Scholarly Interests
I am interested in color centers, quantum optics and scalable solid-state photonics. My goal is to develop new paradigms of communication, computation and sensing by utilizing semiconductor nanofabrication and quantum laws of light-matter interaction.
Cavity-Enhanced Raman Emission from a Single Color Center in a Solid.
Physical review letters
2018; 121 (8): 083601
We demonstrate cavity-enhanced Raman emission from a single atomic defect in a solid. Our platform is a single silicon-vacancy center in diamond coupled with a monolithic diamond photonic crystal cavity. The cavity enables an unprecedented frequency tuning range of the Raman emission (100GHz) that significantly exceeds the spectral inhomogeneity of silicon-vacancy centers in diamond nanostructures. We also show that the cavity selectively suppresses the phonon-induced spontaneous emission that degrades the efficiency of Raman photon generation. Our results pave the way towards photon-mediated many-body interactions between solid-state quantum emitters in a nanophotonic platform.
View details for DOI 10.1103/PhysRevLett.121.083601
View details for PubMedID 30192607
- Quantum Properties of Dichroic Silicon Vacancies in Silicon Carbide PHYSICAL REVIEW APPLIED 2018; 9 (3)
Strongly Cavity-Enhanced Spontaneous Emission from Silicon-Vacancy Centers in Diamond
2018; 18 (2): 1360–65
Quantum emitters are an integral component for a broad range of quantum technologies, including quantum communication, quantum repeaters, and linear optical quantum computation. Solid-state color centers are promising candidates for scalable quantum optics due to their long coherence time and small inhomogeneous broadening. However, once excited, color centers often decay through phonon-assisted processes, limiting the efficiency of single-photon generation and photon-mediated entanglement generation. Herein, we demonstrate strong enhancement of spontaneous emission rate of a single silicon-vacancy center in diamond embedded within a monolithic optical cavity, reaching a regime in which the excited-state lifetime is dominated by spontaneous emission into the cavity mode. We observe 10-fold lifetime reduction and 42-fold enhancement in emission intensity when the cavity is tuned into resonance with the optical transition of a single silicon-vacancy center, corresponding to 90% of the excited-state energy decay occurring through spontaneous emission into the cavity mode. We also demonstrate the largest coupling strength (g/2π = 4.9 ± 0.3 GHz) and cooperativity (C = 1.4) to date for color-center-based cavity quantum electrodynamics systems, bringing the system closer to the strong coupling regime.
View details for DOI 10.1021/acs.nanolett.7b05075
View details for Web of Science ID 000425559700102
View details for PubMedID 29377701
Scalable Quantum Photonics with Single Color Centers in Silicon Carbide.
Silicon carbide is a promising platform for single photon sources, quantum bits (qubits), and nanoscale sensors based on individual color centers. Toward this goal, we develop a scalable array of nanopillars incorporating single silicon vacancy centers in 4H-SiC, readily available for efficient interfacing with free-space objective and lensed-fibers. A commercially obtained substrate is irradiated with 2 MeV electron beams to create vacancies. Subsequent lithographic process forms 800 nm tall nanopillars with 400-1400 nm diameters. We obtain high collection efficiency of up to 22 kcounts/s optical saturation rates from a single silicon vacancy center while preserving the single photon emission and the optically induced electron-spin polarization properties. Our study demonstrates silicon carbide as a readily available platform for scalable quantum photonics architecture relying on single photon sources and qubits.
View details for DOI 10.1021/acs.nanolett.6b05102
View details for PubMedID 28225630
Observation of Mollow Triplets with Tunable Interactions in Double Lambda Systems of Individual Hole Spins
PHYSICAL REVIEW LETTERS
2017; 118 (1)
Although individual spins in quantum dots have been studied extensively as qubits, their investigation under strong resonant driving in the scope of accessing Mollow physics is still an open question. Here, we have grown high quality positively charged quantum dots embedded in a planar microcavity that enable enhanced light-matter interactions. Under a strong magnetic field in the Voigt configuration, individual positively charged quantum dots provide a double lambda level structure. Using a combination of above-band and resonant excitation, we observe the formation of Mollow triplets on all optical transitions. We find that when the strong resonant drive power is used to tune the Mollow-triplet lines through each other, we observe anticrossings. We also demonstrate that the interaction that gives rise to the anticrossings can be controlled in strength by tuning the polarization of the resonant laser drive. Quantum-optical modeling of our system fully captures the experimentally observed spectra and provides insight on the complicated level structure that results from the strong driving of the double lambda system.
View details for DOI 10.1103/PhysRevLett.118.013602
View details for Web of Science ID 000391474000011
View details for PubMedID 28106434
- Photon blockade in two-emitter-cavity systems Physical Review A 2017; 96 (011801(R))
- Nonclassical Light Generation From III-V and Group-IV Solid-State Cavity Quantum Systems ADVANCES IN ATOMIC, MOLECULAR, AND OPTICAL PHYSICS, VOL 66 2017; 66: 111–79
Complete Coherent Control of Silicon-Vacancies in Diamond Nanopillars Containing Single Defect Centers
View details for Web of Science ID 000427296200411
- Thermally tunable III-V photonic crystals for coherent nonlinear optical circuits SPIE-INT SOC OPTICAL ENGINEERING. 2017
Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers
2016; 16 (1): 212-217
We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV(-)) color centers in diamond as quantum emitters. Hybrid diamond-SiC structures are realized by combining the growth of nano- and microdiamonds on silicon carbide (3C or 4H polytype) substrates, with the subsequent use of these diamond crystals as a hard mask for pattern transfer. SiV(-) color centers are incorporated in diamond during its synthesis from molecular diamond seeds (diamondoids), with no need for ion-implantation or annealing. We show that the same growth technique can be used to grow a diamond layer controllably doped with SiV(-) on top of a high purity bulk diamond, in which we subsequently fabricate nanopillar arrays containing high quality SiV(-) centers. Scanning confocal photoluminescence measurements reveal optically active SiV(-) lines both at room temperature and low temperature (5 K) from all fabricated structures, and, in particular, very narrow line widths and small inhomogeneous broadening of SiV(-) lines from all-diamond nanopillar arrays, which is a critical requirement for quantum computation. At low temperatures (5 K) we observe in these structures the signature typical of SiV(-) centers in bulk diamond, consistent with a double lambda. These results indicate that high quality color centers can be incorporated into nanophotonic structures synthetically with properties equivalent to those in bulk diamond, thereby opening opportunities for applications in classical and quantum information processing.
View details for DOI 10.1021/acs.nanolett.5b03515
View details for Web of Science ID 000368322700034
- Visible Photoluminescence from Cubic (3C) Silicon Carbide Microdisks Coupled to High Quality Whispering Gallery Modes ACS PHOTONICS 2015; 2 (1): 14-19
- Multimode nanobeam cavities for nonlinear optics: high quality resonances separated by an octave OPTICS EXPRESS 2014; 22 (22): 26498-26509
- Nonlinear frequency conversion using high-quality modes in GaAs nanobeam cavities OPTICS LETTERS 2014; 39 (19): 5673-5676
- Second-Harmonic Generation in GaAs Photonic Crystal Cavities in (111)B and (001) Crystal Orientations ACS PHOTONICS 2014; 1 (6): 516-523
Photonic crystal cavities in cubic (3C) polytype silicon carbide films
2013; 21 (26): 32623-32629
We present the design, fabrication, and characterization of high quality factor (Q ~103) and small mode volume (V ~0.75 (λ/n)3) planar photonic crystal cavities from cubic (3C) thin films (thickness ~200 nm) of silicon carbide (SiC) grown epitaxially on a silicon substrate. We demonstrate cavity resonances across the telecommunications band, with wavelengths from 1.25 - 1.6 μm. Finally, we discuss possible applications in nonlinear optics, optical interconnects, and quantum information science.
View details for DOI 10.1364/OE.21.032623
View details for Web of Science ID 000329205200088
View details for PubMedID 24514856
- Second harmonic generation in photonic crystal cavities in (111)-oriented GaAs APPLIED PHYSICS LETTERS 2013; 103 (21)