Research

PhD research

Topological photonics and photonic machine learning

Supervisor: Prof. Mohammad Hafezi, JQI, University of Maryland, USA

Brief description: Designed coupled ring resonator-based photonic devices (silicon nitride, lithium niobate) using ab initio analytical techniques and commercial software like ANSYS Lumerical, Tidy3D, COMSOL, and Zemax. Performed tapeout and characterization of said devices for engineering optical nonlinearity for frequency comb generation and photonic computing.

Publications: 

1. Mahmoud Jalali Mehrabad*, Lida Xu*, et al. Multi-timescale frequency–phase matching for high-yield nonlinear photonics. arXiv:2506.15016 (2025). (*authors contributed equally)

Optically probing strongly correlated electronic states

Supervisor: Prof. Mohammad Hafezi, JQI, University of Maryland, USA

Collaborators: Prof. You Zhou (University of Maryland), Prof. Atac Imamoglu (ETH Zurich), Prof. Michael Knap (TU Munich)

Brief description: Experimentally using tools from photonics, quantum optics, and light-matter interaction to explore many-body physics, topology, and chirality in condensed matter systems like two-dimensional materials, aimed towards understanding exotic phases of matter.

Publications: 

1. Pranshoo Upadhyay*, Daniel G. Suárez-Forero*, Tsung-Sheng Huang*, Mahmoud Jalali Mehrabad, Beini Gao, Supratik Sarkar, Deric Session, Kenji Watanabe, Takashi Taniguchi, You Zhou, Michael Knap, Mohammad Hafezi. Giant enhancement of exciton diffusion near an electronic Mott insulator. arXiv:2409.18357 (2024).

2. Beini Gao*, Daniel G. Suárez-Forero*, Supratik Sarkar*, Tsung-Sheng Huang, Deric Session, Mahmoud Jalali Mehrabad, Ruihao Ni, Ming Xie, Pranshoo Upadhyay, Jonathan Vannucci, Sunil Mittal, Kenji Watanabe, Takashi Taniguchi, Atac Imamoglu, You Zhou, Mohammad Hafezi. Excitonic Mott insulator in a Bose-Fermi-Hubbard system of moiré WS2/WSe2 heterobilayer. Nature Communications 15, 2305 (2024).  (*authors contributed equally)

Near-field control of 2D materials with nano-plasmonics

Supervisor: Prof. Mohammad Hafezi, JQI, University of Maryland, USA

Collaborator: Prof. You Zhou (University of Maryland)

Publication: Supratik Sarkar*, Mahmoud Jalali Mehrabad*, Daniel G. Suárez-Forero*, Liuxin Gu*, Christopher J. Flower, Lida Xu, Kenji Watanabe, Takashi Taniguchi, Suji Park, Houk Jang, You Zhou, Mohammad Hafezi. Sub-wavelength optical lattice in 2D materials. Science Advances 11, eadv2023 (2025).  (*authors contributed equally) [Featured🌟]

Chiral Optical Nano-Cavity with Atomically Thin Mirrors

Supervisor: Prof. Mohammad Hafezi, JQI, University of Maryland, USA

Collaborator: Prof. You Zhou (University of Maryland)

Publication: Daniel G. Suárez-Forero*, Ruihao Ni*, Supratik Sarkar*, Mahmoud Jalali Mehrabad*, Erik Mechtel, Valery Simonyan, Andrey Grankin, Kenji Watanabe, Takashi Taniguchi, Suji Park, Houk Jang, Mohammad Hafezi, You Zhou. Chiral flat-band optical cavity with atomically thin mirrors. Science Advances 10, eadr5904 (2024). (*authors contributed equally) [Featured🌟]

Masters research

Designing optical antennas with Inverse Design for enhanced directional emission of radiation from NV centers

Supervisor: Prof. Michal Bajcsy, IQC, University of Waterloo, Canada

Brief description: Engineered diamond nanophotonic devices that allow for highly directional emission of radiation from NV centers compared to traditional techniques, using adjoint optimization and inverse design techniques.

Publication: Behrooz Semnani et al. Probing individual quantum emitters in bulk semiconductors via photonic nanojets. (2025) [Coming soon]

Deterministic single photon subtraction using SPRINT in a three-level emitter for engineering exotic non-classical states of light

Supervisor: Prof. Michal Bajcsy, IQC, University of Waterloo, Canada

Brief description: Performed analytical and numerical analysis to propose methods of deterministic single photon subtraction from any arbitrary state of light using a single quantum emitter coupled with a chiral waveguide or a cavity to engineer exotic non-classical states of light.

Undergraduate research

Undergraduate Final Year Project: Tunneling in Graphene SymFETs

Supervisor: Prof. Chayanika Bose, Jadavpur University, India

Report: Supratik Sarkar, and Samrat Sarkar, Tunneling in Graphene SymFETs, arXiv: 1805.09659 (2018).

Single Photon Subtraction from Continuous Variable Cluster States

Supervisor: Prof. Nicolas Treps, LKB (CNRS, ENS, UPMC-Sorbonne), France 

Publication: Mattia Walschaers, Supratik Sarkar, Valentina Parigi, and Nicolas Treps. Tailoring Non-Gaussian Continuous-Variable Graph States. Physical Review Letters 121, 220501 (2018).

Influence of Polarization and Self-polarization Charges on Impurity Binding Energy in Spherical Quantum Dot with Parabolic Confinement

Supervisor: Prof. Chayanika Bose, Jadavpur University, India

Publication: Supratik Sarkar, Samrat Sarkar, and Chayanika Bose. Influence of polarization and self-polarization charges on impurity binding energy in spherical quantum dot with parabolic confinement. Physica B: Condensed Matter 541, 75-78 (2018).

Detection of Celiac Disease from Endoscopy Images Using Convolutional Neural Networks

Supervisor: Prof. Debdoot Sheet, Indian Institute of Technology (IIT) Kharagpur, India

True Random Number Generators

Supervisor: Prof. Subhamoy Maitra, Indian Statistical Institute (ISI) Kolkata, India