123 citations · 1k across the 40 of their papers we have counts for
40 papers
Semidefinite programming for understanding the limitations of Lindblad equations
Soumyadeep Sarma, Manas Kulkarni, Archak Purkayastha +1
Lindbladian quantum master equations (LEs) are the most popular descriptions for quantum systems weakly coupled to baths. But, recent works have established that in many situations…
Quantum non-Markovian Hatano-Nelson model
Sumit Kumar Jana, Ryo Hanai, Tan Van Vu +2
While considering non-Hermitian Hamiltonians arising in the presence of dissipation, in most cases, the dissipation is taken to be frequency independent. However, this idealization…
Accelerated calculation of impurity Green's functions exploiting the extreme Mpemba effect
David J. Strachan, Archak Purkayastha, Stephen R. Clark
Simulating the dynamics of quantum impurity models remains a fundamental challenge due to the complex memory effects that arise from system-environment interactions. Of particular…
Extracting Dynamical Maps of Non-Markovian Open Quantum Systems
David J. Strachan, Archak Purkayastha, Stephen R. Clark
The most general description of quantum evolution up to a time is a completely positive tracing preserving map known as a dynamical map . Here we consider …
On the difference between thermalization in open and isolated quantum systems: a case study
Archak Purkayastha, Giacomo Guarnieri, Janet Anders +1
Thermalization of isolated and open quantum systems has been studied extensively. However, being the subject of investigation by different scientific communities and being analysed…
Arbitrary order transfer matrix exceptional points and van Hove singularities
Madhumita Saha, Bijay Kumar Agarwalla, Manas Kulkarni +1
In lattice models with quadratic finite-range Hermitian Hamiltonians, the inherently non-Hermitian transfer matrix (TM) governs the band dispersion. The van Hove singularities (VHS…
Effect of order of transfer matrix exceptional points on transport at band edges
Madhumita Saha, Bijay Kumar Agarwalla, Manas Kulkarni +1
Recently, it has been shown that, in one dimensional fermionic systems, close to band edges, the zero temperature conductance scales as , where is the system length. Thi…
Non-Markovian Quantum Mpemba effect
David J. Strachan, Archak Purkayastha, Stephen R. Clark
Since it's rediscovery in the twentieth century, the Mpemba effect, where a far-from-equilibrium state may relax faster than a state closer to equilibrium, has been extensively stu…
Nonclassical radiation from a nonlinear oscillator driven solely by classical noise
Archak Purkayastha, Klaus Mølmer
Low-frequency classical -noise and quantum noise from low-temperature phonon modes are ubiquitous across various experimental platforms, and are usually considered a hindrance…
Interaction-induced transition in quantum many-body detection probability
Archak Purkayastha, Alberto Imparato
With the advent of digital and analog quantum simulation experiments, it is now possible to experimentally simulate dynamics of quantum many-body lattice systems and make site-reso…
Searching for Lindbladians obeying local conservation laws and showing thermalization
Devashish Tupkary, Abhishek Dhar, Manas Kulkarni +1
We investigate the possibility of a Markovian quantum master equation (QME) that consistently describes a finite-dimensional system, a part of which is weakly coupled to a thermal…
Quantum correlations in dissipative gain-loss systems across exceptional points
Federico Roccati, Archak Purkayastha, G. Massimo Palma +1
We investigate the behavior of correlations dynamics in a dissipative gain-loss system. First, we consider a setup made of two coupled lossy oscillators, with one of them subject t…
Particle current statistics in driven mesoscale conductors
Marlon Brenes, Giacomo Guarnieri, Archak Purkayastha +3
We propose a highly-scalable method to compute the statistics of charge transfer in driven conductors. The framework can be applied in situations of non-zero temperature, strong co…
Accumulative reservoir construction: Bridging continuously relaxed and periodically refreshed extended reservoirs
Gabriela Wojtowicz, Archak Purkayastha, Michael Zwolak +1
The simulation of open many-body quantum systems is challenging, requiring methods to both handle exponentially large Hilbert spaces and represent the influence of (infinite) parti…
Environment assisted superballistic scaling of conductance
Madhumita Saha, Bijay Kumar Agarwalla, Manas Kulkarni +1
We find that, in the presence of weak incoherent effects from surrounding environments, the zero temperature conductance of nearest neighbour tight-binding chains exhibits a counte…
Quantum thermodynamics with fast driving and strong coupling via the mesoscopic leads approach
Artur M. Lacerda, Archak Purkayastha, Michael Kewming +2
Understanding the thermodynamics of driven quantum systems strongly coupled to thermal baths is a central focus of quantum thermodynamics and mesoscopic physics. A variety of diffe…
Universal subdiffusive behavior at band edges from transfer matrix exceptional points
Madhumita Saha, Bijay Kumar Agarwalla, Manas Kulkarni +1
We discover a deep connection between parity-time (PT) symmetric optical systems and quantum transport in one-dimensional fermionic chains in a two-terminal open system setting. Th…
Lyapunov equation in open quantum systems and non-Hermitian physics
Archak Purkayastha
The continuous-time differential Lyapunov equation is widely used in linear optimal control theory, a branch of mathematics and engineering. In quantum physics, it is known to appe…
Dephasing-enhanced performance in quasiperiodic thermal machines
Cecilia Chiaracane, Archak Purkayastha, Mark T. Mitchison +1
Understanding and controlling quantum transport in low-dimensional systems is pivotal for heat management at the nanoscale. One promising strategy to obtain the desired transport p…
Fundamental limitations in Lindblad descriptions of systems weakly coupled to baths
Devashish Tupkary, Abhishek Dhar, Manas Kulkarni +1
It is very common in the literature to write down a Markovian quantum master equation in Lindblad form to describe a system with multiple degrees of freedom and weakly connected to…
Sub-diffusive phases in open clean long-range systems
Archak Purkayastha, Madhumita Saha, Bijay Kumar Agarwalla
We show that a one-dimensional ordered fermionic lattice system with power-law-decaying hopping, when connected to two baths at its two ends with different chemical potentials at z…
Time periodicity from randomness in quantum systems
Giacomo Guarnieri, Mark T. Mitchison, Archak Purkayastha +3
Many complex systems can spontaneously oscillate under non-periodic forcing. Such self-oscillators are commonplace in biological and technological assemblies where temporal periodi…
Taking the temperature of a pure quantum state
Mark T. Mitchison, Archak Purkayastha, Marlon Brenes +2
Temperature is a deceptively simple concept that still raises deep questions at the forefront of quantum physics research. The observation of thermalisation in completely isolated…
Quantum dynamics in the interacting Fibonacci chain
Cecilia Chiaracane, Francesca Pietracaprina, Archak Purkayastha +1
Quantum dynamics on quasiperiodic geometries has recently gathered significant attention in ultra-cold atom experiments where non trivial localised phases have been observed. One s…