Publications (25)
Enhancing the Energy Gap of Random Graph Problems via XX-catalysts in Quantum Annealing
Luca A. Nutricati, Roopayan Ghosh, Natasha Feinstein +2
One of the bottlenecks in solving combinatorial optimisation problems using quantum annealers is the emergence of exponentially-closing energy gaps between the ground state and the…
Exponentially-enhanced quantum sensing with many-body phase transitions
Saubhik Sarkar, Abolfazl Bayat, Sougato Bose +1
Quantum sensors based on critical many-body systems are known to exhibit enhanced sensing capability. Such enhancements typically scale algebraically with the probe size. Going bey…
Signatures of multifractality in a periodically driven interacting Aubry-André model
Madhumita Sarkar, Roopayan Ghosh, Arnab Sen +1
We study the many-body localization (MBL) transition of Floquet eigenstates in a driven, interacting fermionic chain with an incommensurate Aubry-André potential and a time-period…
Conformal Floquet dynamics with a continuous drive protocol
Diptarka Das, Roopayan Ghosh, Krishnendu Sengupta
We study the properties {of a conformal field theory} (CFT) driven periodically with a continuous protocol characterized by a frequency . Such a drive, in contrast to its dis…
Response to `Comment on Theory of growth of number entropy in disordered systems'
Roopayan Ghosh, Marko ŽnidariÄ
In a recent preprint by Kiefer-Emmanouilidis, Unanyan, Fleischhauer and Sirker [arxiv:2203.06689] the authors comment on our work which studied the number entropy in strongly disor…
Mobility edge and multifractality in a periodically driven Aubry-André model
Madhumita Sarkar, Roopayan Ghosh, Arnab Sen +1
We study the localization-delocalization transition of Floquet eigenstates in a driven fermionic chain with an incommensurate Aubry-André potential and a hopping amplitude which i…
Re-entrant localization induced by short-range hopping in the fractal Rosenzweig-Porter Model
Roopayan Ghosh, Madhumita Sarkar, Ivan M. Khaymovich
Typically, metallic systems localized under strong disorder exhibit a transition to \imk{delocalization} %finite conduction as kinetic terms increase. In this work, we reveal the o…
Boundary Chaos: Exact Entanglement Dynamics
Felix Fritzsch, Roopayan Ghosh, Tomaž Prosen
We compute the dynamics of entanglement in the minimal setup producing ergodic and mixing quantum many-body dynamics, which we previously dubbed {\em boundary chaos}. This consists…
A Floquet perturbation theory for periodically driven weakly-interacting fermions
Roopayan Ghosh, Bhaskar Mukherjee, K. Sengupta
We compute the Floquet Hamiltonian for weakly interacting fermions subjected to a continuous periodic drive using a Floquet perturbation theory (FPT) with the interaction amp…
Gadgets for simulating a non-native interaction in quantum annealing
Robert J. Banks, Natasha Feinstein, Roopayan Ghosh +2
In certain scenarios, quantum annealing can be made more efficient by additional interactions. It has been shown that the additional interactions can reduce the scaling of per…
Relaxation of imbalance in a disordered XX model with on-site dephasing
Roopayan Ghosh, Marko ŽnidariÄ
The relaxation of observables to their non-equilibrium steady states in a disordered XX chain subjected to dephasing at every site has been intensely studied in recent years. We co…
Harmonic Control of Dynamical Freezing in Programmable Rydberg Atom Arrays
Madhumita Sarkar, Ben Zindorf, Bhaskar Mukherjee +2
Periodic driving enables the engineering of complex quantum matter, yet in interacting systems it generically leads to energy absorption, which limits the lifetime of the engineere…
Resonance-induced growth of number entropy in strongly disordered systems
Roopayan Ghosh, Marko ŽnidariÄ
We study the growth of the number entropy in one-dimensional number-conserving interacting systems with strong disorder, which are believed to display many-body localization.…
Tuning the phase diagram of a Rosenzweig-Porter model with fractal disorder
Madhumita Sarkar, Roopayan Ghosh, Ivan M. Khaymovich
Rosenzweig-Porter (RP) model has garnered much attention in the last decade, as it is a simple analytically tractable model showing both ergodic--nonergodic extended and Anderson l…
Entanglement measures and non-equilibrium dynamics of quantum many-body systems: a path integral approach
Roopayan Ghosh, Nicolas Dupuis, Arnab Sen +1
We present a path integral formalism for expressing matrix elements of the density matrix of a quantum many-body system between any two coherent states in terms of standard Matsuba…
Spin qubit gates via phonon buses in electron nanowires
Dylan Lewis, Roopayan Ghosh, Sanjeev Kumar +4
Scalable architectures for quantum computing using semiconductor quantum dots require interactions between qubits beyond adjacent quantum dots. Here, we propose using nanowires of…
Separability criterion using one observable for special states: Entanglement detection via quantum quench
Roopayan Ghosh, Sougato Bose
Detecting entanglement in many-body quantum systems is crucial but challenging, typically requiring multiple measurements. Here, we establish the class of states where measuring co…
Disorder-induced Enhancement of Entanglement Growth in One Dimension: Information Leakage at the scale of localization length
Roopayan Ghosh, Arnab Das
When a group of compactly packed free fermions is allowed to spread over an empty one-dimensional lattice, the spreading particles can create entanglement between different parts o…
Self-Attention for Quantum Entanglement Prediction
Anuj Gore, Roopayan Ghosh, Dylan Lewis +1
Quantum entanglement is a powerful resource for quantum-enhanced technologies. However, its reliable quantification remains challenging due to the exponential scaling of the Hilber…
All-Electric Quantum State Transfer via Spin-Orbit Phase Matching
Madhumita Sarkar, Roopayan Ghosh, Charles G. Smith +2
Semiconductor hole-spin qubits offer a promising route to quantum computation due to their weak hyperfine interaction, and strong intrinsic spin-orbit coupling enabling electric co…
Anomalous suppression of quantum chaos between two integrable limits
Roopayan Ghosh, Henry Davenport, Frank Schindler
Level statistics in non-integrable quantum many-body systems with time reversal symmetry are expected to follow the Gaussian Orthogonal Ensemble (GOE), a hallmark of quantum chaos.…
Magnetization induced dynamics of a Josephson junction coupled to a nanomagnet
Roopayan Ghosh, Moitri Maiti, Yury M. Shukrinov +1
We study the superconducting current of a Josephson junction (JJ) coupled to an external nanomagnet driven by a time dependent magnetic field both without and in the presence of an…
Quantum Liang Information Flow Probe of Causality across Critical Points
Roopayan Ghosh, Bin Yi, Sougato Bose
Investigating causation in the quantum domain is crucial. Despite numerous studies of correlations in quantum many-body systems, causation, which is very distinct from correlations…
Ramp and periodic dynamics across non-Ising critical points
Roopayan Ghosh, Arnab Sen, K. Sengupta
We study ramp and periodic dynamics of ultracold bosons in an one-dimensional (1D) optical lattice which supports quantum critical points separating a uniform and a or …
Enhancement of quantum annealing via n-local catalysts
Roopayan Ghosh, Luca A. Nutricati, Natasha Feinstein +2
The potential quantum speedup in solving optimization problems via adiabatic quantum annealing is often hindered by the closing of the energy gap during the anneal, especially when…