212 citations · 1.5k across the 55 of their papers we have counts for
55 papers
On the emergence of quantum many-body chaos for tunably-broken integrability
Sounak Biswas, Sthitadhi Roy, Roderich Moessner
We develop a quantitative theory for the emergence of quantum many-body chaos as integrability is broken via a tunable parameter. In a circuit model of free fermions, 'doped' with…
How many-body chaos emerges in the presence of quasiparticles
Sibaram Ruidas, Sthitadhi Roy, Subhro Bhattacharjee +1
Many-body chaos is a default property of many-body systems; at the same time, near-integrable behaviour due to weakly interacting quasiparticles is ubiquitous throughout condensed…
Multifractality in high-dimensional graphs induced by correlated radial disorder
David E. Logan, Sthitadhi Roy
We introduce a class of models containing robust and analytically demonstrable multifractality induced by disorder correlations. Specifically, we investigate the statistics of eige…
Logarithmic entanglement lightcone from eigenstate correlations in the many-body localised phase
Ratul Thakur, Bikram Pain, Sthitadhi Roy
We investigate the operator entanglement of the time-evolution operator through the framework of eigenstate correlations. Focusing on strongly disordered quantum many-body systems…
Projected ensemble in a system with conserved charges with local support
Sandipan Manna, Sthitadhi Roy, G. J. Sreejith
The investigation of ergodicity or lack thereof in isolated quantum many-body systems has conventionally focused on the description of the reduced density matrices of local subsyst…
Measurement-invisible quantum correlations in scrambling dynamics
Alan Sherry, Sthitadhi Roy
Scrambling unitary dynamics in a quantum system transmutes local quantum information into a non-local web of correlations which manifests itself in a complex spatio-temporal patter…
The Fock-space landscape of many-body localisation
Sthitadhi Roy, David E. Logan
This article reviews recent progress in understanding the physics of many-body localisation (MBL) in disordered and interacting quantum many-body systems, from the perspective of e…
Entanglement dynamics and eigenstate correlations in strongly disordered quantum many-body systems
Bikram Pain, Sthitadhi Roy
The many-body localised phase of quantum systems is an unusual dynamical phase wherein the system fails to thermalise and yet, entanglement grows unboundedly albeit very slowly in…
Spectral Multifractality and Emergent Energyscales Across the Many-Body Localisation Transition
Sthitadhi Roy
We present a scaling theory of the many-body localisation transition in terms of emergent, characteristic energyscales. The analysis is based on the decomposition of the eigenstate…
Anatomy of localisation protected quantum order on Hilbert space
Sthitadhi Roy
Many-body localised phases of disordered, interacting quantum systems allow for exotic localisation protected quantum order in eigenstates at arbitrarily high energy densities. In…
The connection between Hilbert-space return probability and real-space autocorrelations in quantum spin chains
Bikram Pain, Kritika Khanwal, Sthitadhi Roy
The dynamics of interacting quantum many-body systems has two seemingly disparate but fundamental facets. The first is the dynamics of real-space local observables, and if and how…
Eigenvector Correlations Across the Localisation Transition in non-Hermitian Power-Law Banded Random Matrices
Soumi Ghosh, Manas Kulkarni, Sthitadhi Roy
The dynamics of non-Hermitian quantum systems have taken on an increasing relevance in light of quantum devices which are not perfectly isolated from their environment. The interes…
Probability transport on the Fock space of a disordered quantum spin chain
Isabel Creed, David E. Logan, Sthitadhi Roy
Within the broad theme of understanding the dynamics of disordered quantum many-body systems, one of the simplest questions one can ask is: given an initial state, how does it evol…
Hilbert-space correlations beyond multifractality and bipartite entanglement in many-body localised systems
Sthitadhi Roy
Eigenstates of many-body localised (MBL) systems are characterised by area-law bipartite entanglement along with multifractal statistics of their amplitudes on Hilbert space. At th…
Constrained Dynamics and Directed Percolation
Aydin Deger, Achilleas Lazarides, Sthitadhi Roy
In a recent work [A. Deger et al., Phys. Rev. Lett. 129, 160601 (2022)] we have shown that kinetic constraints can completely arrest many-body chaos in the dynamics of a classical,…
Real-time correlators in chaotic quantum many-body systems
Adam Nahum, Sthitadhi Roy, Sagar Vijay +1
We study real-time local correlators in chaotic quantum many-body systems. These correlators show universal structure at l…
Scaling of Fock-space propagator and multifractality across the many-body localization transition
Jagannath Sutradhar, Soumi Ghosh, Sthitadhi Roy +3
We implement a recursive Green function method to extract the Fock space (FS) propagator and associated self-energy across the many-body localization (MBL) transition, for one-dime…
Arresting classical many-body chaos by kinetic constraints
Aydin Deger, Sthitadhi Roy, Achilleas Lazarides
We investigate the effect of kinetic constraints on classical many-body chaos in a translationally-invariant Heisenberg spin chain using a classical counterpart of the out-of-time-…
Resonant energy scales and local observables in the many-body localised phase
Samuel J. Garratt, Sthitadhi Roy
We formulate a theory for resonances in the many-body localised (MBL) phase of disordered quantum spin chains in terms of local observables. A key result is to show that there are…
Anomalous multifractality in quantum chains with strongly correlated disorder
Alexander Duthie, Sthitadhi Roy, David E. Logan
We demonstrate numerically that a robust and unusual multifractal regime can emerge in a one-dimensional quantum chain with maximally correlated disorder, above a threshold disorde…
Absolutely Stable Spatiotemporal Order in Noisy Quantum Systems
Max McGinley, Sthitadhi Roy, S. A. Parameswaran
We introduce a model of non-unitary quantum dynamics that exhibits infinitely long-lived discrete spatiotemporal order robust against any unitary or dissipative perturbation. Ergod…
Local resonances and parametric level dynamics in the many-body localised phase
S. J. Garratt, Sthitadhi Roy, J. T. Chalker
By varying the disorder realisation in the many-body localised (MBL) phase, we investigate the influence of resonances on spectral properties. The standard theory of the MBL phase…
Fock-space anatomy of eigenstates across the many-body localisation transition
Sthitadhi Roy, David E. Logan
We explore the Fock-space structure of eigenstates across the many-body localisation (MBL) transition in a disordered, interacting quantum spin-1/2 chain. Eigenstate expectation va…
Localisation in quasiperiodic chains: a theory based on convergence of local propagators
Alexander Duthie, Sthitadhi Roy, David E. Logan
Quasiperiodic systems serve as fertile ground for studying localisation, due to their propensity already in one dimension to exhibit rich phase diagrams with mobility edges. The de…