English
Related papers

Related papers: Optimal probes for continuous variable quantum ill…

200 papers

We provide the optimal strategy for unambiguous quantum reading of optical memories, namely when perfect retrieving of information is achieved probabilistically, for the case where noise and loss are negligible. We describe the experimental…

Experimental tests for assessing the physical reality of the hypothetical wave modes of quantum vacuum with zero-point energy are of fundamental importance for quantum field theories and cosmology. Physical effects like the Casimir effect…

Quantum Physics · Physics 2019-12-25 C. S. Unnikrishnan

Quantum illumination uses quantum entanglement as a resource to enable higher-resolution detection of low-reflectivity targets than is possible with classical techniques. This revolutionary technology could transform modern radar. However,…

Quantum Physics · Physics 2025-10-24 Wei Wu , Jun-Hong An

Under some physical considerations, we present a universal formulation to study the possibility of localizing a quantum object in a given region without disturbing its unknown internal state. When the interaction between the object and…

Quantum Physics · Physics 2009-11-07 Zheng-Wei Zhou , Xingxiang Zhou , Marc J. Feldman , Guang-Can Guo

The characterization of continuous-variable quantum states is crucial for applications in quantum communication, sensing, simulation and computing. However, a full characterization of multimode quantum states requires a number of…

Quantum Physics · Physics 2024-10-08 Ya-Dong Wu , Yan Zhu , Giulio Chiribella , Nana Liu

Microwave quantum illumination with entangled pairs of microwave signal and optical idler modes, can achieve the sub-optimal performance with joint measurement of the signal and idler modes. Here, we first propose a testbed of microwave…

Quantum Physics · Physics 2024-05-24 Sangwoo Jeon , Jihwan Kim , Duk Y. Kim , Zaeill Kim , Taek Jeong , Su-Yong Lee

Quantum technologies exploit entanglement to enhance various tasks beyond their classical limits including computation, communication and measurements. Quantum metrology aims to increase the precision of a measured quantity that is…

Quantum Physics · Physics 2020-08-25 Bálint Koczor , Suguru Endo , Tyson Jones , Yuichiro Matsuzaki , Simon C. Benjamin

This paper investigates the quickest change detection of quantum states in a universal setting: specifically, where the post-change quantum state is not known a priori. We establish the asymptotic optimality of a two-stage approach in terms…

Quantum Physics · Physics 2026-04-21 Arick Grootveld , Haodong Yang , Nandan Sriranga , Biao Chen , Venkata Gandikota , Jason Pollack

We theoretically and experimentally investigate conditional enhancement of overall coherence of quantum states by probabilistic quantum operations that apply to the input state a quantum filter diagonal in the basis of incoherent states. We…

Quantum Physics · Physics 2021-08-03 Robert Stárek , Michal Mičuda , Michal Kolář , Radim Filip , Jaromír Fiurášek

We consider the problem of a state determination for a two-level quantum system which can be in one of two nonorthogonal mixed states. It is proved that for the two independent identical systems the optimal combined measurement (which…

Quantum Physics · Physics 2007-05-23 A. E. Allahverdyan , D. B. Saakian

Quantum illumination is a quantum-optical sensing technique in which an entangled source is exploited to improve the detection of a low-reflectivity object that is immersed in a bright thermal background. Here we describe and analyze a…

Optimal phase estimation of a phase-squeezed quantum state of light has been recently shown to beat the coherent-state limit. Here, the estimation is made robust to uncertainties in underlying parameters using a robust fixed-interval…

Quantum Physics · Physics 2015-09-14 Shibdas Roy , Ian R. Petersen , Elanor H. Huntington

We consider a device which can be programmed using coherent states of light to approximate a given projective measurement on an input coherent state. We provide and discuss three practical implementations of this programmable projective…

Quantum Physics · Physics 2022-07-26 Niraj Kumar , Ulysse Chabaud , Elham Kashefi , Damian Markham , Eleni Diamanti

Quantum illumination (QI) is the task of querying a scene using a transmitter probe whose quantum state is entangled with a reference beam retained in ideal storage, followed by optimally detecting the target-returned light together with…

Quantum Physics · Physics 2024-11-08 Ali Cox , Quntao Zhuang , Jeffrey H. Shapiro , Saikat Guha

We investigate the dynamics for a two level atomic system entangled to coherent states using the recently developed mode invisibility technique. Using a quantum 2-level probe, we demonstrate a way to non-destructively measure a number of…

Quantum Physics · Physics 2017-10-04 Paulina Corona-Ugalde , Marvellous Onuma-Kalu , Robert B. Mann

Phase-insensitive optical amplifiers uniformly amplify each quadrature of an input field and are of both fundamental and technological importance. We find the quantum limit on the precision of estimating the gain of a quantum-limited…

Quantum Physics · Physics 2022-05-09 Ranjith Nair , Guo Yao Tham , Mile Gu

Quantum illumination is a quantum-optical sensing technique in which an entangled source is exploited to improve the detection of a low-reflectivity object that is immersed in a bright thermal background. Here we describe and analyze a…

We present a theoretical study of minimum error probability discrimination, using quantum- optical probe states, of M optical phase shifts situated symmetrically on the unit circle. We assume ideal lossless conditions and full freedom for…

Quantum Physics · Physics 2012-08-14 Ranjith Nair , Brent J. Yen , Saikat Guha , Jeffrey H. Shapiro , Stefano Pirandola

We present methods for efficient characterization of an optical coherent state $|\alpha\rangle$. We choose measurement settings adaptively and stochastically, based on data while it is collected. Our algorithm divides the estimation into…

Quantum Physics · Physics 2016-01-08 Markku P. V. Stenberg , Kevin Pack , Frank K. Wilhelm

In a quantum illumination (QI) protocol, the task is to detect the presence of the target which is typically modelled by a partially reflecting beam splitter. We analyze the performance of QI when the target absorbs part of the light that…

Quantum Physics · Physics 2021-11-02 Rivu Gupta , Saptarshi Roy , Tamoghna Das , Aditi Sen De