activity
20232026
most citedQuantum sensing of even- versus odd-body interactions

3 citations · 12 across the 24 of their papers we have counts for

collaborators

24 papers

quant-ph2026

Towards minimal conditions for ergotropy injection in open quantum systems

Deependra Singh, Debarupa Saha, Ujjwal Sen

Interactions between a quantum system and its environment can inject ergotropy into the system, raising the question of the minimal dimensionality and physical resources required f…

quant-ph2026

Remote predictability of quantum measurement outcomes

Chirag Srivastava, Aparajita Bhattacharyya, Sheikh Parvez Mandal +2

Predicting quantum measurement outcomes for a local observer makes sense before, but not after, the measurement. However, for a remote observer, predicting measurement outcomes eve…

quant-ph2026

Enhanced quantum state discrimination under general measurements with entanglement and nonorthogonality restrictions

Swati Choudhary, Aparajita Bhattacharyya, Ujjwal Sen

The minimum error probability for distinguishing between two quantum states is bounded by the Helstrom limit, derived under the assumption that measurement strategies are restricte…

quant-ph2026

Precision Enhancement in Transient Quantum Thermometry:Cold-Probe Bias and Its Removal

Debarupa Saha, Ujjwal Sen

We unveil a fundamental temperature bias in transient quantum thermometry under Markovian dynamics. For qubit probes evolving in a thermal Markovian environment, we prove that tran…

quant-ph2025

Non-positive measurements aren't beneficial in quantum metrology for unitary encoding, but can be for open schemes

Paranjoy Chaki, Debarupa Saha, Kornikar Sen +1

We investigate whether non-positive operator-valued measurements can be beneficial for quantum metrology. For unitary encoding, we show that non-positive measurements offer no adva…

quant-ph2025

Isocoherent Work Extraction from Quantum Batteries: Basis-Dependent Response

Shuva Mondal, Debarupa Saha, Ujjwal Sen

We identify a connection between quantum coherence and the maximum extractable work from a quantum battery, and to this end, we define the coherence-constrained maximal work (CCMW)…

quant-ph2025★ 1 cited

Entanglement-Constrained Quantum Metrology: Rapid Low-Entanglement Gains, Tapered High-Level Growth

Debarupa Saha, Ujjwal Sen

It is a specific type of quantum correlated state that achieves optimal precision in parameterestimation under unitary encoding. We consider the potential experimental limitation o…

quant-ph2025

Quantum refrigerator embedded in spin-star environments: Scalings of temperature and refrigeration time

Sukrut Mondkar, Aparajita Bhattacharyya, Ujjwal Sen

We examine a quantum absorption refrigerator that comprises three qubits, each of which is connected with a separate spin-star environment, with the three qubit-bath units coupled…

quant-ph2025

Distributed Quantum Dense Coding Enhanced With Non-classical Routing

Pratham Hullamballi, Aparajita Bhattacharyya, Ujjwal Sen

We propose a distributed quantum dense coding protocol that uses a control system to superpose two dense coding processes, allowing us to simultaneously and coherently encode and n…

quant-ph2025

Non-Markovianity vs athermality: perturbation-enhanced information backflow

Anindita Sarkar, Debarupa Saha, Ujjwal Sen

Non-Markovianity and athermality are useful resources in quantum technologies, and it is therefore important to understand the relations between the two, for general quantum dynami…

quant-ph2025

Quantum transistors for heat flux in and out of working substance parts: harmonic vs transmon and Kerr environs

Deepika Bhargava, Paranjoy Chaki, Aparajita Bhattacharyya +1

Quantum thermal transistors have been widely studied in the context of three-qubit systems, where each qubit interacts separately with a Markovian harmonic bath. Markovianity is an…

quant-ph2024

Nonlinearity-assisted advantage for open Dicke-quantum batteries

Aparajita Bhattacharyya, Pratha Dongre, Ujjwal Sen

We analyze the performance of a quantum battery in terms of energy storage and energy extraction, assisted by nonlinearities in a Dicke quantum battery utilizing an open-system app…

quant-ph2024

Approximate second laws and energy extraction from quantum batteries

Debarupa Saha, Aparajita Bhattacharyya, Ujjwal Sen

Conservation of energy under thermal operations, \textbf{TO}, is ensured by commutation of the unitary generating such operations with the total Hamiltonian. However in realistic s…

quant-ph2024★ 2 cited

Role of energy-invariant assistants in energy extraction from quantum batteries

Paranjoy Chaki, Aparajita Bhattacharyya, Kornikar Sen +1

We investigate the role of energy-invariant assistants in energy extraction from quantum batteries. To this end, for energy extraction, we restrict ourselves to unitaries that join…

quant-ph2024

Precision in estimating independent local fields: attainable bound and indispensability of genuine multiparty entanglement

Aparajita Bhattacharyya, Ujjwal Sen

Estimation of local quantum fields is a crucial aspect of quantum metrology applications, and often also forms the test-bed to analyze the utility of quantum resources, like entang…

quant-ph2024★ 1 cited

Positive and non-positive measurements in energy distillation from quantum batteries

Paranjoy Chaki, Aparajita Bhattacharyya, Kornikar Sen +1

We investigate energy distillation from quantum batteries within the framework of generalized quantum measurements, including both positive operator-valued measurements (POVMs) and…

quant-ph2024

Quantum Heat Transformers

Arghya Maity, Paranjoy Chaki, Ahana Ghoshal +1

We propose a quantum heat transformer (QHT), a quantum thermodynamic device that modulates temperature gradients between two thermal junctions in quantum systems. Functionally, the…

quant-ph2024★ 1 cited

Minimal-error quantum state discrimination versus robustness of entanglement:More indistinguishability with less entanglement

Debarupa Saha, Kornikar Sen, Chirag Srivastava +1

We relate the the distinguishability of quantum states with their robustness of the entanglement, where the robustness of any resource quantifies how tolerant it is to noise. In pa…

quant-ph2024★ 3 cited

Quantum sensing of even- versus odd-body interactions

Aparajita Bhattacharyya, Debarupa Saha, Ujjwal Sen

We analyze the scaling of quantum Fisher information with the number of system particles in the limit of large number of particles, as a function of the number of parties interacti…

quant-ph2023★ 1 cited

Measurement incompatibility at all remote parties do not always permit Bell nonlocality

Priya Ghosh, Chirag Srivastava, Swati Choudhary +1

Two important ingredients necessary for obtaining Bell nonlocal correlations between two spatially separated parties are an entangled state shared between them and an incompatible…

quant-ph2023

Kerr-type nonlinear baths enhance cooling in quantum refrigerators

Tanaya Ray, Sayan Mondal, Aparajita Bhattacharyya +3

We study the self-contained three-qubit quantum refrigerator, with a three-body interaction enabling cooling of the target qubit, in presence of baths composed of anharmonic quantu…

quant-ph2023★ 2 cited

Harnessing energy extracted from heat engines to charge quantum batteries

Debarupa Saha, Aparajita Bhattacharyya, Kornikar Sen +1

We explore the performance of three- and two-stroke heat engines with a qutrit working substance in charging two-level quantum batteries. We first classify the heat engines into tw…

quant-ph2023★ 1 cited

Temperature- and interaction-tweaked efficiency boost of finite-time robust quantum Otto engines

Debarupa Saha, Ahana Ghoshal, Ujjwal Sen

We demonstrate that under specific conditions, a finite-time quantum Otto engine, employing a spin-1/2 particle as the working substance, despite undergoing incomplete Otto cycles,…

quant-ph2023

Modified Landauer's principle: How much can the Maxwell's demon gain by using general system-environment quantum state?

Sayan Mondal, Aparajita Bhattacharyya, Ahana Ghoshal +1

The Landauer principle states that decrease in entropy of a system, inevitably leads to a dissipation of heat to the environment. This statement is usually established by consideri…