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DR. ARNAB ACHARYA WEIZMANN INSTITUTE
LATTICE: COHERENT
Postdoctoral Excellence Fellow

Dr. Arnab Acharya Postdoctoral Fellow

Department of Chemical and Biological Physics, Weizmann Institute of Science. Specializing in spin dynamics simulations, Lie-algebraic integrators, optimizing matrix exponential-vector routines (expmv), and quantum optimal control.

Weizmann Institute of Science, Israel
Ph.D. from IISER Kolkata (2024)
View Papers Academic CV
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Research Frontiers

Quantum Collapse, Coherence & Chaos

Exploring foundational processes in quantum dynamics, focusing on open systems, wave collapse mechanisms, and periodic position measurements.

Driven Quantum Impact Oscillators

Investigating nonlinear quantum systems that hit elastic boundaries. Modeling strange nonchaotic dynamics, singular-continuous (multifractal) spectra, and localized quantum structures in ultracold atomic cantilevers.

v⁺ = -r v⁻ | boundary x = 0

Objective Collapse Models

Studying interaction-induced wave collapse and testing macro-object triggers. Finding regimes where objective collapse deviates from conventional quantum formulations, offering experimental signatures.

dρ/dt = -i[H, ρ] + Λ(ρ)

Periodic Measurements & Open Systems

Exploring periodic position measurements of harmonic oscillators. Proving measurement-induced state localization in potential wells, showing robustness against external decoherence and ambient noise.

ρₙ₊₁ = Mₓ ρₙ Mₓ† / Tr(Mₓ ρₙ Mₓ†)
Postdoctoral & Active Research Programs

Active Projects & Research Plans

Recent work at the Weizmann Institute on structure-preserving time propagation, open quantum systems, and diamond nitrogen-vacancy (NV) center control.

Active Research Plan

Structure-Preserving Time Evolution

Developing geometric and Lie-algebraic integrators (Magnus, commutator-free exponential) to simulate driven spin dynamics. Guarantees unitarity, trace, and positivity preservation under periodic driving fields.

HPC / Spinach Koshland Focus
Active Research Plan

Open-System & Environment Models

Simulating molecular bath environments and non-Markovian memory effects in Spinach without exponential complexity. Applicable to decoherence in molecular magnets and metabolomic MRI relaxation.

Open-Quantum Dynamics Kuprov Lab
Active Research Plan

Ensemble-Aware & Robust Control

Extending optimal control sequences (GRAPE, Reinforcement Learning) to remain robust against environmental noise, sample inhomogeneity, and experimental offsets in NMR, ESR, and MRI.

Quantum Control Robustness
diamondQ Project SVN

Selective Single-Spin NV Manipulation

Optimal control simulations in dense statistical NV center systems (Method I) and artificial 2D NV arrays (Method II). Using strong 3D micro-gradients (up to 19,000 T/m/A) to generate spatial qubit selectivity.

Spinach / MATLAB Method I & II
diamondQ Project SVN

P1 Gradient Transition Spectrum

Analyzing hyperfine tensor alignments and P1 center transitions under extreme static magnetic field gradients (B0 = 0.22 T). Mapping spatial transition peaks for multi-target spin addressing protocols.

Dynamic Address Finkler Group
Computational Forge

Scientific HPC & Numerical Models

Writing performance-critical algorithms for large-dimensional systems. Expert in parallel, GPU, and vector-optimized physics simulations using Julia and MATLAB.

Algorithms & Frameworks:

Split-operator Fourier methods, Magnus expansions for periodic systems, and Numerov-Cooley grid shooting methods.

Chaos Diagnostics:

Implementation of the 0-1 test for chaos, Poincaré sections, bifurcation diagrams, and Lyapunov exponents.

Picard–Lefschetz Theory:

Evaluating highly oscillatory path integrals in anisotropic quantum cosmology models.

split_operator_propagate.jl - VS Code
Julia
using FFTW # Split-Operator FFT Propagator for Time-Dependent Schrödinger Eq. function split_operator_step(psi::Vector{ComplexF64}, V::Vector{Float64}, dt::Real, dx::Real, mass::Real) N = length(psi) # Define momentum coordinate array p = fftshift(-N/2 : N/2 - 1) * (2π / (N * dx)) # Position and kinetic energy operator exponentials U_V = exp.(-im * V * dt / 2.0) U_T = exp.(-im * (p.^2 / (2.0 * mass)) * dt) # Perform split propagation steps (V/2 -> T -> V/2) psi_half = U_V .* psi psi_k = fft(psi_half) psi_k_prop = U_T .* psi_k psi_x = ifft(psi_k_prop) return U_V .* psi_x end
Publications Database

Scientific Bibliography

Peer-reviewed articles, letters, and preprints detailing quantum measurements, cosmological path integrals, and open systems.

Initializing publications matrix...
Academic Matrix

Curriculum & Experience

Chronology of research appointments, teaching duties, and institutional degrees.

Timeline Vertical scroll inside

DEC 2025 – PRESENT Weizmann Fellowship

Postdoctoral Excellence Fellow

Weizmann Institute of Science, Rehovot, Israel

Group of Prof. Ilya Kuprov. Specializing in spin dynamics simulations, Lie-algebraic integrators, optimizing matrix exponential-vector routines (expmv), and quantum optimal control (GRAPE/RL hot-start acceleration).

SEP 2025 – NOV 2025

Project Assistant

Indian Institute of Science Education and Research (IISER) Kolkata

Assisting in research concerning driven quantum dynamics, chaotic transitions, and stroboscopic measurements.

JULY 2024 – MAY 2025

Ad-hoc Assistant Professor

Visvesvaraya National Institute of Technology (VNIT), Nagpur

Lecturing physics core modules to undergraduate engineering students.

2017 – 2024 CSIR-NET Rank 20

Ph.D. in Physical Sciences

Indian Institute of Science Education and Research (IISER) Kolkata

Thesis Advisor: Prof. Soumitro Banerjee. Focus on Driven Non-Smooth Quantum Dynamics, Floquet chaos, strange nonchaotic attractors, and path integral formulations. Thesis: "Driven Non-Smooth Quantum Systems." Qualified CSIR-NET in Lectureship with All India Rank 20 (2022).

2015 – 2017

M.S. in Physical Sciences

Indian Institute of Science Education and Research (IISER) Kolkata

Integrated MS program. Coursework in quantum mechanics, statistical mechanics, condensed matter, and electrodynamics. Research in quantum measurements.

2010 – 2014 JEST Qualified

B.Tech. in Electrical Engineering

National Institute of Technology (NIT) Durgapur

Foundation in electrical networks, control systems, and electronics. Shifted focus to theoretical physics during undergraduate research projects. Qualified Joint Entrance Screening Test (JEST) in 2014.

Awards & Ranks

  • Weizmann Postdoctoral Excellence Fellowship (2026)
  • CSIR-NET Lectureship Rank 20 (2022)
  • SERB International Travel Support (2023)
  • JEST Qualified (2014)

Contact & Links

arnab.acharya@weizmann.ac.il LinkedIn Profile ORCID Profile Google Scholar GitHub Profile