Quantum thermal absorption machines: refrigerators, engines and clocks

MT Mitchison - Contemporary Physics, 2019 - Taylor & Francis
The inexorable miniaturisation of technologies, the relentless drive to improve efficiency and
the enticing prospect of boosting performance through quantum effects are all compelling …

Effective-Hamiltonian theory of open quantum systems at strong coupling

N Anto-Sztrikacs, A Nazir, D Segal - PRX Quantum, 2023 - APS
We present the reaction-coordinate polaron-transform (RCPT) framework for generating
effective-Hamiltonian models to treat nonequilibrium open quantum systems at strong …

Fundamental limitations in Lindblad descriptions of systems weakly coupled to baths

D Tupkary, A Dhar, M Kulkarni, A Purkayastha - Physical Review A, 2022 - APS
It is very common in the literature to write a Markovian quantum master equation in Lindblad
form to describe a system with multiple degrees of freedom and weakly connected to …

Weak and ultrastrong coupling limits of the quantum mean force Gibbs state

JD Cresser, J Anders - Physical review letters, 2021 - APS
The Gibbs state is widely taken to be the equilibrium state of a system in contact with an
environment at temperature T. However, non-negligible interactions between system and …

Non-markovian quantum Mpemba effect

DJ Strachan, A Purkayastha, SR Clark - arxiv preprint arxiv:2402.05756, 2024 - arxiv.org
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 …

Searching for Lindbladians obeying local conservation laws and showing thermalization

D Tupkary, A Dhar, M Kulkarni, A Purkayastha - Physical Review A, 2023 - APS
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 …

Exploiting coherence for quantum thermodynamic advantage

K Hammam, H Leitch, Y Hassouni… - New Journal of …, 2022 - iopscience.iop.org
The introduction of the quantum analogue of a Carnot engine based on a bath comprising of
particles with a small amount of coherence initiated an active line of research on the …

Tunable phonon-induced steady-state coherence in a double-quantum-dot charge qubit

A Purkayastha, G Guarnieri, MT Mitchison… - npj Quantum …, 2020 - nature.com
Charge qubits can be created and manipulated in solid-state double-quantum-dot (DQD)
platforms. Typically, these systems are strongly affected by quantum noise stemming from …

Nonlocal advantage of quantum coherence in a dephasing channel with memory

ML Hu, YH Zhang, H Fan - Chinese Physics B, 2021 - iopscience.iop.org
We investigate nonlocal advantage of quantum coherence (NAQC) in a correlated
dephasing channel modeled by the multimode bosonic reservoir. We obtain analytically the …

Enhancing two-qubit quantum coherence in a correlated dephasing channel

M Hu, W Zhou - Laser Physics Letters, 2019 - iopscience.iop.org
We investigate how the classical correlations between successive actions of a colored
dephasing channel affect the decoherence of a two-qubit system. Our calculation shows that …