English
Related papers

Related papers: Non-classical state generation in macroscopic syst…

200 papers

Measures of quantum properties are essential to understanding the fundamental differences between quantum and classical systems as well as quantifying resources for quantum technologies. Here two broad classes of bosonic phase-space…

Quantum Physics · Physics 2021-05-11 Benjamin Kühn , Werner Vogel , Valérian Thiel , Sofiane Merkouche , Brian J. Smith

We generalise a non-classicality test described by Kot et al. [Phys. Rev. Lett. 108, 233601 (2010)], which can be used to rule out any classical description of a physical system. The test is based on measurements of quadrature operators and…

Quantum Physics · Physics 2015-12-16 Luca Fresta , Johannes Borregaard , Anders S. Sørensen

Nonclassical mechanical states, as vital quantum resources for exploring macroscopic quantum behavior, have wide applications in the study of the fundamental quantum mechanics and modern quantum technology. In this work, we propose a scheme…

Quantum Physics · Physics 2025-05-26 Yu-Hong Liu , Qing-Shou Tan , Le-Man Kuang , Jie-Qiao Liao

The initial state creation is a starting point of many quantum algorithms and usually is considered as a separate subroutine not included into the algorithm itself. There are many algorithms aimed on creation of special class of states. Our…

Quantum Physics · Physics 2025-05-01 Alexander I. Zenchuk , Wentao Qi , Junde Wu

We propose a method to generate nonclassical states of light in multimode microwave cavities. Our approach considers two-photon processes that take place in a system composed of two extended cavities and an ultrastrongly coupled…

Quantum Physics · Physics 2019-03-28 F. A. Cárdenas-López , G. Romero , L. Lamata , E. Solano , J. C. Retamal

The quadrature coherence scale (QCS) is a recently introduced measure that was shown to be an efficient witness of nonclassicality. It takes a simple form for pure and Gaussian states, but a general expression for mixed states tends to be…

Quantum Physics · Physics 2024-07-03 Anaelle Hertz , Aaron Z. Goldberg , Khabat Heshami

In this letter, we present a simple and versatile scheme for enhancing the nonclassical properties of light states using only linear optics and photodetectors. By combining a coherent state $|\alpha\rangle$ and an arbitrary pure state of…

Quantum Physics · Physics 2023-10-17 E. P. Mattos , A. Vidiella-Barranco

Generalized quantum measurements are an important extension of projective or von Neumann measurements, in that they can be used to describe any measurement that can be implemented on a quantum system. We describe how to realize two…

We analyze the performance of a protocol to prepare an atomic ensemble in a superposition of two macroscopically distinguishable states. The protocol relies on conditional measurements performed on a light field, which interacts with the…

Quantum Physics · Physics 2009-02-28 Anne E. B. Nielsen , Uffe V. Poulsen , Antonio Negretti , Klaus Molmer

Nonclassical states, having no classical analogue, promise advantage in the performance in several fields of technology, such as computation, communication, sensing. This led to an escalated interest in the recent years for the generation…

Quantum Physics · Physics 2018-05-22 Kishore Thapliyal

A new measure of non-classical correlations is introduced and characterized. It tests the ability of using a state {\rho} of a composite system AB as a probe for a quantum illumination task [e.g. see S. Lloyd, Science 321, 1463 (2008)], in…

Quantum Physics · Physics 2014-07-17 A. Farace , A. De Pasquale , L. Rigovacca , V. Giovannetti

We study nonclassical effects in the dynamics of an open quantum system. The model involves a harmonic oscillator coupled to a reservoir of non-interacting harmonic oscillators. Different system-bath interaction schemes as well as reservoir…

Quantum Physics · Physics 2023-05-17 Mehdi Abdi , Moslem Zarei

We propose a system of equations to describe the interaction of a quasiclassical variable $X$ with a set of quantum variables $x$ that goes beyond the usual mean field approximation. The idea is to regard the quantum system as continuously…

Quantum Physics · Physics 2009-10-30 L. Diosi , J. J. Halliwell

Non-classical probability (along with its underlying logic) is a defining feature of quantum mechanics. A formulation that incorporates them, inherently and directly, would promise a unified description of seemingly different prescriptions…

Quantum Physics · Physics 2019-05-21 Soumik Adhikary , Sooryansh Asthana , V. Ravishankar

Quantum state tomography (QST) is the gold standard technique for obtaining an estimate for the state of small quantum systems in the laboratory. Its application to systems with more than a few constituents (e.g. particles) soon becomes…

Fock states and their superpositions are exotic testbeds for nonclassical physics and valuable resources for quantum technologies. We provide a simple protocol for the quantum measurement to generate an arbitrary Fock state and certain…

Quantum Physics · Physics 2024-10-22 Chen-yi Zhang , Jun Jing

The well known metrological linear squeezing parameters (such as quadrature or spin squeezing) efficiently quantify the sensitivity of Gaussian states. Yet, these parameters are insufficient to characterize the much wider class of highly…

Quantum Physics · Physics 2019-03-11 Manuel Gessner , Augusto Smerzi , Luca Pezzè

We derive the stochastic master equations, that is to say, quantum filters, and master equations for an arbitrary quantum system probed by a continuous-mode bosonic input field in two types of non-classical states. Specifically, we consider…

Quantum Physics · Physics 2012-10-17 J. E. Gough , M. R. James , H. I. Nurdin , Joshua Combes

We address the joint estimation of changes in the position and linear momentum of a quantum particle or, equivalently, changes in the complex field of a bosonic mode. Although these changes are generated by non-commuting operators, we show…

Quantum state discrimination is a fundamental information processing task that serves as a building block for numerous applications and provides implications at the foundational level. In this work, we consider minimum error discrimination…

Quantum Physics · Physics 2026-04-30 Tim Achenbach , Leevi Leppäjärvi , Hanwool Lee , Teiko Heinosaari