6 papers
No-Go Theorem for Ancilla-Assisted Gaussian Enhancement in Passive-Unitary Estimation
Zihao Gong, Saikat Guha
We study the maximum quantum Fisher information (QFI) for estimating a single parameter embedded in a generic multimode lossless passive Gaussian unitary using general Gaussian pro…
Passive optical superresolution at the quantum limit
A. I. Lvovsky, Michael R. Grace, Saikat Guha +3
For more than a century, the diffraction limit has defined the resolution achievable by passive optical imaging systems. Although some resolution improvement can be gained through…
Non-Markovian delay-assisted sensing with waveguide-coupled quantum emitters
Prajit Dhara, Isack Padilla, Saikat Guha +2
We show that in a minimal setup of two waveguide-coupled quantum emitters, separated by long distances and subject to an external field, time-delayed feedback can be a resource for…
Quantum-enhanced Network Tomography
Yufei Zheng, Zihao Gong, Saikat Guha +1
Network tomography refers to the use of inference techniques for inferring internal network states from end-to-end probes. Quantum probes, implemented by sending blocks of cohe…
Boosted linear-optical measurements on single-rail qubits with unentangled ancillas
Aqil Sajjad, Isack Padilla, Saikat Guha
Any quantum state of the radiation field, sliced in small non-overlapping space-time bins is a collection of single-rail qubits, each spanning the vacuum and single-photon Fock sta…
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…