Abhishek Raj portrait

Abhishek Raj

Postdoc. CS . Stony Brook University

Ph.D. Physics · CUNY

Int. M.Tech Engineering Physics · IIT (BHU), Varanasi

Quantum Computing • Cryptography • Nonlinear Dynamics • Many-Body Physics

About Me

I am a theoretical physicist working at the interface of quantum many-body physics, non‑equilibrium statistical mechanics, quantum information and post quantum cryptography. I build analytical models and high‑performance simulations to study complex systems. Recently, I’ve been developing efficient hardware‑oriented implementations of Shor’s algorithm for ECC (ECDLP) and exploring quantum error correction and post‑quantum security.

Research

My work uncovers emergent transport phenomena in kinetically constrained and non-linear systems, including non‑perturbative diffusion cascades and jamming transitions. Recently I have been interested in the intersection of many‑body physics and quantum error correction (QEC) (quantum LDPC codes, tensor‑network constructions) and separately in quantum cryptanalysis and PQC.

Research Timeline

2025 — Quantum Cryptanalysis & Shor’s Algorithm for ECC

Hardware‑efficient ECDLP circuits in Qiskit: ECC group ops, scalar multiplication, and QFT‑based period finding; Classical post‑processing.

2024 — Jamming in Kinetically Constrained Models

Triangular‑ladder model with coexisting diffusive and jammed phases; classical–quantum mapping and Hartree–Fock analysis of quasiparticles.

2023 — Nonlinear Diffusion & Hydrodynamic Cascades

Identified stretched‑exponential relaxation via diffusion cascades; large‑scale numerical simulations and stochastic field theory.

2021 — Plaquette Ising Model & Dualities

Phase structure under transverse fields; mapping to Quantum Compass model; DMRG and ML‑assisted wavefunction approximations.

2018 — Many‑Body Localization & Quenches

Localization length distributions, interferometric probes, and integrability diagnostics in disordered spin chains.

Publications

Length scales in the many-body localized phase and their spectral signatures

Phys. Rev. B 100, 115136

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Diffusion cascade in a model of interacting random walkers

arXiv:2412.05222

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A kinetically constrained model exhibiting non-linear diffusion and jamming

J. Stat. Mech. (2025) 073208

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Highlighted Projects

Quantum Attack on Elliptic Curve Cryptography

Qiskit implementation of Shor’s ECDLP with ECC group ops, QFT, and Classical post‑processing.

View on GitHub

Nonlinear Diffusion Simulations

GPU‑accelerated lattice‑gas simulations to study hydrodynamic cascades and jamming.

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Integrability in Quantum Systems

Distinguishing Integrable and Non Integrable Systems using Quantum Quenches.

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Quantum Machine Learning Experiments

Hybrid QML algorithms combining Qiskit and PyTorch for kernel estimation and VQCs.

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RAG Application

LLM-based application for document summarization and inference.

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Plaquette Ising

Phase transitions and duality in Plaquette Ising Model.

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News & Updates

Curriculum Vitae

You can download my full CV below.

Contact