12 citations · 48 across the 12 of their papers we have counts for
12 papers
What is a Gaussian channel, and when is it physically implementable using a multiport interferometer?
Repana Devendra, Tiju Cherian John, K. Sumesh
Quantum Gaussian channels are fundamental models for communication and information processing in continuous-variable quantum systems. This work addresses both foundational aspects…
A Complete Characterization of Passive Unitary Normalizable (PUN) Gaussian States
Tiju Cherian John, Hemant K. Mishra, Saikat Guha
We provide a complete characterization of the class of multimode quantum Gaussian states that can be reduced to a tensor product of thermal states using only a passive unitary oper…
Fundamental Limits Of Quickest Change-point Detection With Continuous-Variable Quantum States
Tiju Cherian John, Christos N. Gagatsos, Boulat A. Bash
We generalize the quantum CUSUM (QUSUM) algorithm for quickest change-point detection, analyzed in finite dimensions by Fanizza, Hirche, and Calsamiglia (Phys. Rev. Lett. 131, 0206…
Quantum-enhanced quickest change detection of transmission loss
Saikat Guha, Tiju Cherian John, Zihao Gong +1
Augmenting a train of bright phase-modulated laser-light pulses of a coherent communications system with infinitesimally small quantum photons per pulse -- entangled across several…
Quantum -divergences via Nussbaum-Szkoła Distributions and Applications to -divergence Inequalities
George Androulakis, Tiju Cherian John
The main result in this article shows that the quantum -divergence of two states is equal to the classical -divergence of the corresponding Nussbaum-Szkoła distributions. Thi…
Thermal States on Mittag-Leffler Fock Space of the Slitted Plane
Natanael Alpay, Tiju Cherian John
Number states and thermal states form an important class of physical states in quantum theory. A mathematical framework for studying these states is that of a Fock space over an ap…
Petz-Rényi Relative Entropy of Thermal States and their Displacements
George Androulakis, Tiju Cherian John
In this article, we obtain the precise range of the values of the parameter such that Petz-Rényi -relative entropy of two displaced thermal states is finite. Mor…
An Order Relation between Eigenvalues and Symplectic Eigenvalues of a Class of Infinite-Dimensional Operators
Tiju Cherian John, V. B. Kiran Kumar, Anmary Tonny
In this article, we obtain some results in the direction of ``infinite dimensional symplectic spectral theory". We prove an inequality between the eigenvalues and symplectic eigenv…
Relative Entropy via Distribution of Observables
George Androulakis, Tiju Cherian John
We obtain formulas for Petz-Rényi and Umegaki relative entropy from the idea of distribution of a positive selfadjoint operator. Classical results on Rényi and Kullback-Leibler div…
A Common Parametrization for Finite Mode Gaussian States, their Symmetries and associated Contractions with some Applications
Tiju Cherian John, K. R. Parthasarathy
Let be the boson Fock space over a finite dimensional Hilbert space . It is shown that every gaussian symmetry admits a Klauder-Bargmann integral repr…
Infinite Mode Quantum Gaussian States
B. V. Rajarama Bhat, Tiju Cherian John, R. Srinivasan
Quantum Gaussian states on Bosonic Fock spaces are quantum versions of Gaussian distributions. In this paper, we explore infinite mode quantum Gaussian states. We extend many of th…
Real Normal Operators and Williamson's Normal Form
B V Rajarama Bhat, Tiju Cherian John
A simple proof is provided to show that any bounded normal operator on a real Hilbert space is orthogonally equivalent to its transpose(adjoint). A structure theorem for invertible…