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Related papers: Fidelity for displaced squeezed states and the osc…

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Two measures of fidelity are proposed for postselecting devices, the retrodictive conditional probability that the state in the measurement arm is the one indicated by the detectors, and the probability that the device produces the state…

Quantum Physics · Physics 2009-11-13 John Jeffers

The fidelity of two pure states (also known as transition probability) is a symmetric function of two operators, and well-founded operationally as an event probability in a certain preparation-test pair. Motivated by the idea that the…

Quantum Physics · Physics 2009-11-06 Andreas Winter

An adaptive method for quantum state fidelity estimation in bipartite higher dimensional systems is established. This method employs state verifier operators which are constructed by local POVM operators and adapted to the measurement…

Quantum Physics · Physics 2020-09-17 Jun-Yi Wu

Squeezed state in harmonic systems can be generated through a variety of techniques, including varying the oscillator frequency or using nonlinear two-photon Raman interaction. We focus on these two techniques to drive an initial thermal…

Quantum Physics · Physics 2021-05-04 Léonce Dupays , Aurélia Chenu

We study experimentally the thermal fluctuations of energy input and dissipation in a harmonic oscillator driven out of equilibrium, and search for Fluctuation Relations. We study transient evolution from the equilibrium state, together…

Statistical Mechanics · Physics 2007-11-28 Sylvain Joubaud , Nicolas Garnier , Sergio Ciliberto

Using the f-deformed oscillator formalism, we introduce two types of squeezed coherent states for a Morse potential system (Morse-like squeezed coherent states) through the following definitions: i) as approximate eigenstates of a linear…

Quantum Physics · Physics 2018-06-05 Octavio de los Santos Sánchez , José Récamier

We propose a reliable entanglement measure for a two-mode squeezed thermal state of the quantum electromagnetic field in terms of its Bures distance to the set of all separable states of the same kind. The requisite Uhlmann fidelity of a…

Quantum Physics · Physics 2007-05-23 Paulina Marian , Tudor A. Marian , Horia Scutaru

We propose a displacement-operator approach to some aspects of squeezed states for general multiphoton systems. The explicit displacement-operators of the squeezed vacuum and the coherent states are achieved and expresses as the ordinary…

Quantum Physics · Physics 2008-02-03 Hong-Chen Fu , Ryu Sasaki

Motivated by recent development in quantum fidelity and fidelity susceptibility, we study relations among Lie algebra, fidelity susceptibility and quantum phase transition for a two-state system and the Lipkin-Meshkov-Glick model. We get…

Quantum Physics · Physics 2011-04-11 Li-Jun Tian , Chang-Qing Zhu , Hong-Biao Zhang , Li-Guo Qin

In this paper, we investigate a thermal coherent state defined with the Lie-Trotter product formula under the formalism of the thermo field dynamics. In the definition of our thermal coherent state, we treat the thermalizing operator and…

Quantum Physics · Physics 2015-07-14 Hiroo Azuma , Masashi Ban

After beginning with a short historical review of the concept of displaced (coherent) and squeezed states, we discuss previous (often forgotten) work on displaced and squeezed number states. Next, we obtain the most general displaced and…

Quantum Physics · Physics 2009-10-30 Michael Martin Nieto

The Bures distance between two displaced thermal states and the corresponding geometric quantities (statistical metric, volume element, scalar curvature) are computed. Under nonunitary (dissipative) dynamics, the statistical distance shows…

Quantum Physics · Physics 2009-10-30 Gh. - S. Paraoanu , Horia Scutaru

We define mixed states associated with submanifolds with probability densities in quantizable closed K{\"a}hler manifolds. Then, we address the problem of comparing two such states via their fidelity. Firstly, we estimate the sub-fidelity…

Mathematical Physics · Physics 2018-08-15 Yohann Le Floch

Both the coherent states and also the squeezed states of the harmonic oscillator have long been understood from the three classical points of view: the 1) displacement operator, 2) annihilation- (or ladder-) operator, and…

High Energy Physics - Theory · Physics 2007-05-23 Michael Martin Nieto

The expression for the density operator of the damped harmonic oscillator is derived from the master equation in the framework of the Lindblad theory for open quantum systems. Then the von Neumann entropy and effective temperature of the…

Quantum Physics · Physics 2007-05-23 A. Isar

We propose a new approach to quantum phase transitions in terms of the density-functional fidelity, which measures the similarity between density distributions of two ground states in parameter space. The key feature of the approach, as we…

Quantum Physics · Physics 2009-11-13 Shi-Jian Gu

For the displaced harmonic double-well oscillator the existence of exact polynomial bound states at certain displacements $d\,$ is revealed. The $N-$plets of these quasi-exactly solvable (QES) states are constructed in closed form. For…

Mathematical Physics · Physics 2022-08-25 Miloslav Znojil

We study the fidelity susceptibility of two SU(2)-invariant reduced density matrices. Due to the commuting property of these matrices, analytical results for reduced fidelity susceptibility are obtained and can be applied to study quantum…

Quantum Physics · Physics 2008-09-30 Xiaoguang Wang , Shi-Jiang Gu

We give an alternative definition of quantum fidelity for two density operators on qudits in terms of the Hilbert-Schmidt inner product between them and their purity. It can be regarded as the well-defined operator fidelity for the two…

Quantum Physics · Physics 2009-11-13 Xiaoguang Wang , Chang-Shui Yu , X. X. Yi

Established methods for dissipative state preparation typically rely on resolving resonances, limiting the target state fidelity due to competition between the stabilization mechanism and uncontrolled dissipation. We propose a protocol…

Quantum Physics · Physics 2020-06-30 E. Doucet , F. Reiter , L. Ranzani , A. Kamal