collaborators

5 papers

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

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

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-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…