99 citations · 490 across the 39 of their papers we have counts for
40 papers
Pure states are optimal for total energy-constrained quantum channel discrimination
Christos N. Gagatsos
We consider the discrimination of two quantum channels acting on bosonic modes, with a probe state of fixed mean photon number and no ancilla. We prove that pure probes are optimal…
Saturating the Bayesian Nagaoka-Hayashi bound within numerical precision for the depolarization SU(2) rotation channel
Leo Bia, Christos N. Gagatsos
The Bayesian Nagaoka--Hayashi (NH) bound is a semidefinite lower bound on the Bayes risk of multiparameter estimation, tighter than the Bayesian symmertic logarithmic derivative (S…
Optimal Probe State for Phase Estimation Under Covariant Measurement
Qipeng Qian, Christos N. Gagatsos
We study the optimization of input states for phase estimation under covariant measurements. Building on Holevo's framework, which provides the optimal covariant measurement for a…
GHZ is All You Need: Quantum Sensing with VISTA
Oskar Novak, Christos N. Gagatsos, Narayanan Rengaswamy
Quantum metrology holds the potential to enhance magnetic field sensing beyond current limits. However, in the presence of realistic noise, this advantage degrades to the Standard…
Upper bounds on the purity of Wigner positive quantum states that verify the Wigner entropy conjecture
Qipeng Qian, Christos Gagatsos
We present analytical results toward the Wigner entropy conjecture, which posits that among all physical Wigner non-negative states the Wigner entropy is minimized by pure Gaussian…
Comparing Homodyne and Heterodyne Tomography of Quantum States of Light
Rhea P. Fernandes, Andrew J. Pizzimenti, Christos N. Gagatsos +1
Non-Gaussian quantum states are critical resources in photonic quantum information processing, rendering their generation and characterization of increasing importance in quantum o…
Optimal single-mode squeezing for beam displacement sensing
Wenhua He, Christos N. Gagatsos, Dalziel J. Wilson +1
Estimation of an optical beam's transverse displacement is a canonical imaging problem fundamental to numerous optical imaging and sensing tasks. Quantum enhancements to the measur…
Bayesian Greedy Receiver for Pulse Position Modulation without an Error Floor under Thermal Noise
Leo Bia, Christos N. Gagatsos, Saikat Guha
We investigate quantum receiver architectures for demodulation -ary Pulse Position Modulation under thermal noise and photon-starved conditions. Building on the greed receiver f…
Heralded enhancement in quantum state discrimination
Qipeng Qian, Christos N. Gagatsos
The discrimination of quantum states is a central problem in quantum information science and technology. Meanwhile, partial post-selection has emerged as a valuable tool for quantu…
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…
Bayesian quantum estimation of the separation of two incoherent point sources
Boyu Zhou, Saikat Guha, Christos N. Gagatsos
We address the estimation problem of the separation of two arbitrarily close incoherent point sources from the quantum Bayesian point of view, i.e., when a prior probability distri…
Utilizing probabilistic entanglement between sensors in quantum networks
Emily A. Van Milligen, Christos N. Gagatsos, Eneet Kaur +2
One of the most promising applications of quantum networks is entanglement assisted sensing. The field of quantum metrology exploits quantum correlations to improve the precision b…
Wigner non-negative states that verify the Wigner entropy conjecture
Qipeng Qian, Christos N. Gagatsos
We present further progress, in the form of analytical results, on the Wigner entropy conjecture set forth in https://link.aps.org/doi/10.1103/PhysRevA.104.042211 and https://iopsc…
Optimum classical beam position sensing
Wenhua He, Christos N. Gagatsos, Dalziel J. Wilson +1
Beam displacement measurements are widely used in optical sensing and communications; however, their performance is affected by numerous intrinsic and extrinsic factors including b…
Majorization theoretical approach to entanglement enhancement via local filtration
Zacharie Van Herstraeten, Nicolas J. Cerf, Saikat Guha +1
From the perspective of majorization theory, we study how to enhance the entanglement of a two-mode squeezed vacuum (TMSV) state by using local filtration operations. We present se…
Bayesian quantum phase estimation with fixed photon states
Boyu Zhou, Saikat Guha, Christos N. Gagatsos
We consider a two-mode bosonic state with fixed photon number , whose upper and lower modes pick up a phase and respectively. We compute the optimal Fock…
Bayesian minimum mean square error for transmissivity sensing
Boyu Zhou, Boulat A. Bash, Saikat Guha +1
We address the problem of estimating the transmissivity of the pure-loss channel from the Bayesian point of view, i.e., we consider that some prior probability distribution functio…
Exploring the possibility of a complex-valued non-Gaussianity measure for quantum states of light
Andrew J. Pizzimenti, Prajit Dhara, Zacharie Van Herstraeten +2
We consider a quantity that is the differential relative entropy between a generic Wigner function and a Gaussian one. We prove that said quantity is minimized with respect to its…
Transceiver designs to attain the entanglement assisted communications capacity
Ali Cox, Quntao Zhuang, Christos Gagatsos +2
Pre-shared entanglement can significantly boost communication rates in the high thermal noise and low-brightness transmitter regime. In this regime, for a lossy-bosonic channel wit…
Quantum-Enhanced Transmittance Sensing
Zihao Gong, Nathaniel Rodriguez, Christos N. Gagatsos +2
We consider the problem of estimating unknown transmittance of a target bathed in thermal background light. As quantum estimation theory yields the fundamental limits, we emplo…
Demonstration of Entanglement-Enhanced Covert Sensing
Shuhong Hao, Haowei Shi, Christos N. Gagatsos +6
The laws of quantum physics endow superior performance and security for information processing: quantum sensing harnesses nonclassical resources to enable measurement precision unm…
Quantum Multi-Parameter Adaptive Bayesian Estimation and Application to Super-Resolution Imaging
Kwan Kit Lee, Christos Gagatsos, Saikat Guha +1
In Bayesian estimation theory, the estimator attains the minimum mean squared error (MMSE) for estimating a scalar parameter of interest from the observatio…
Non-Gaussian photonic state engineering with the quantum frequency processor
Andrew J. Pizzimenti, Joseph M. Lukens, Hsuan-Hao Lu +3
Non-Gaussian quantum states of light are critical resources for optical quantum information processing, but methods to generate them efficiently remain challenging to implement. He…
Heralded-Multiplexed High-Efficiency Cascaded Source of Dual-Rail Polarization-Entangled Photon Pairs using Spontaneous Parametric Down Conversion
Prajit Dhara, Spencer J. Johnson, Christos N. Gagatsos +2
Deterministic sources of high-fidelity entangled qubit pairs encoded in the dual-rail photonic basis, i.e., presence of a single photon in one of two orthogonal modes, are a key en…