Nanostructure Materials & Devices Laboratory

Welcome to the NMDL!
-- where "Quantum" meets "Information"
        We are an interdisciplinary group focused on "Quantum Nanophotonics" that involves creating and studying on-chip quantum devices and circuits that exploit the first quantum particle-- the photon-- for information sensing , transfer, and processing utilizing the rules of quantum mechanics. It is a foundational subset of the general field of "Quantum Information".
        "Quantum Information" is the signature emerging science and technology of the 21st century to supplement the communication, computing, and sensing / imaging technologies of the 20th century built upon the laws of classical physics. Electrons and photons, employed in large numbers, are the basic "work-horses" of these classical technologies. Employing as few electrons and photons as possible to achieve the same (and new) functions reliably is critical to reducing power consumption per bit of processed information in the exploding world of "Big Data". Creating systems that utilize as few as "single" particles to do the work requires following the laws of quantum mechanics for designing the systems and their fabrication requires building blocks at the nanoscale (typically from 10nm to 200nm).
        Building such on-chip systems demands parallel and well-coordinated efforts in the growth of appropriate combinations of materials with atomic-level control, their structural and chemical characterization, fabricating individual as well as interconnected devices (i.e. circuits) and studying their appropriate optical and electronic properties. Such an effort demands researchers from backgrounds and interests in Materials Science, Chemistry, Chemical Engineering, Physics, Electrical Engineering, and Applied Math.
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Scope of Efforts:
        We utilize (lab facility) a unique suite of material / quantum nanostructure synthesis techniques (ranging from cutting-edge vapor phase to solution chemistry based) with in-situ and real-time growth monitoring and control at the atomic layer scale, structural examination [high-resolution transmission electron microscopy, ex-situ and in-situ atomic force and scanning tunneling microscopy], Quantum optical examination [high-resolution photoluminescence (HRPL), time-resolved HRPL, time-corrected photon studies in Hanbury Brown and Twiss (HBT), unbalanced Mach-Zehnder interferometer and Hong-Ou-Mandel (HOM) interferometer], and electrical and opto-electronic (photocurrent) characterization. We utilize custom-designed state-of-the-art quantum optical instrumentation to probing the quantum optical behavior at the single photon level establishing single photon emission statistics (sub Poissonian) and purity, determining photon indistinguishability, and two-photon interference-the basic phenomena that underlie quantum information.
  • Congratulations to Jiefei Zhang and the team, the paper "On chip scalable highly pure and indistinguishable single photon sources in ordered arrays: Path to Quantum Optical Circuits" is accepted by Science Advances!
  • Our latest news coverage by USC:

Recent Publication
  • J. Zhang, S. Chattaraj, Q. Huang, L. Jordao, S. Lu, and A. Madhukar, "On chip scalable highly pure and indistinguishable single photon sources in ordered arrays: Path to Quantum Optical Circuits." Science Advances. (in press)
  • J. Zhang, Q. Huang, L. Jordao, S. Chattaraj, S. Lu, and A. Madhukar, "Planarized spatially-regular arrays of spectrally uniform single quantum dots as on-chip single photon sources for quantum optical circuits." APL Photonics 5, 11, 116106 (2020). [Link]
  • S. Chattaraj, J. Zhang, S. Lu, and A. Madhukar. "On-Chip Integrated Single Photon Source-Optically Resonant Metastructure Based Scalable Quantum Optical Circuits." IEEE Journal of Quantum Electronics 56, 1, 1-9 (2019). [Link]
  • J. Zhang, S. Chattaraj, S. Lu, and A. Madhukar. "Highly pure single photon emission from spectrally uniform surface-curvature directed mesa top single quantum dot ordered array." Applied Physics Letters 114, 7, 071102 (2019). [Link]
        We are constantly on the look-out for "a few good students". If you have a strong undergraduate degree in science or engineering, if you are self-driven, curious, communicative, committed to PhD, and your passion to learn is greater than the fear of walking unknown territory, then contact Professor Madhukar: Email, and Professor Zhang: Email. We are the place for you!