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The quantum coherence of a multipartite system is investigated when some of the parties are moving with uniform acceleration and the analysis is carried out using the single mode approximation. Due to acceleration the quantum coherence is…

Non Gaussian states and processes are useful resources in quantum information with continuous variables. An experimentally accessible criterion has been proposed to measure the degree of non Gaussianity of quantum states, based on the…

We find a one-parameter Gaussian state for an anharmonic oscillator with quadratic and quartic terms, which depends on the energy expectation value. For the weak coupling constant, the Gaussian state is a squeezed state of the vacuum state.…

Quantum Physics · Physics 2007-05-23 Jung Kon Kim , Sang Pyo Kim , Kwang-Gi Park

The partial transposition(PT) operation is an effecient tool in detecting the inseparability of a mixed state. We give an explicit formula for the PT operation for the continuous variable states in Fock space. We then give the necessary and…

Quantum Physics · Physics 2013-05-29 Wang Xiang-Bin , Matsumoto Keiji , Tomita Akihisa

We consider the physical situations where the resource theories of coherence and thermodynamics play competing roles. In particular, we study the creation of quantum coherence using unitary operations with limited thermodynamic resources.…

Quantum Physics · Physics 2016-06-01 Avijit Misra , Uttam Singh , Samyadeb Bhattacharya , Arun Kumar Pati

A theory of quantum state reduction is advanced. It is based on two principles: (1) Gauge decomposition; (2) Maximum entropy. To wit: (1) The reduction decomposition of a state vector is the Schmidt decomposition with respect to the states…

Quantum Physics · Physics 2009-01-05 Vladimir S. Mashkevich

Unique set of coherent states for the anharmonic oscillator is obtained by requiring i. under the quantum mechanical time evolution a coherent state evolves into another, governed by trajectory in the classical phase space (of a related…

Quantum Physics · Physics 2007-05-23 H. S. Sharatchandra

We investigate manipulations of pure quantum states under incoherent or strictly incoherent operations assisted by a coherence battery, that is, a storage device whose degree of coherence is allowed to fluctuate in the process. This leads…

Quantum Physics · Physics 2018-09-26 Benjamin Morris , Gerardo Adesso

Quantum universal invariants of a Gaussian state's covariance matrix, which can be derived from intensity correlation moments, have been adopted to characterize the entanglement properties of Gaussian states via the positive partial…

Quantum Physics · Physics 2026-05-01 Ze-Shan He , Yukuan Zhao , Hao-Shu Tian , Kai Sun , Xiao-Ye Xu , Chuan-Feng Li , Guang-Can Guo

We review recent work on the foundations of thermodynamics in the light of quantum information theory. We adopt a resource-theoretic perspective, wherein thermodynamics is formulated as a theory of what agents can achieve under a particular…

Quantum coherence as an important physical resource plays the key role in implementing various quantum tasks, whereas quantum coherence is often deteriorated due to the noise. In this paper, we analyse under which dynamical conditions the…

Quantum Physics · Physics 2024-08-22 Zhaofang Bai , Shuanping Du

We give a rigorous definition of moments of an unbounded observable with respect to a quantum state in terms of Yosida's approximations of unbounded generators of contractions semigroups. We use this notion to characterize Gaussian states…

Mathematical Physics · Physics 2023-08-07 Jorge R. Bolaños-Servín , Roberto Quezada , Josué I. Rios-Cangas

We propose a practical strategy for choosing sets of input coherent states that are near-optimal for reconstructing single-mode Gaussian quantum processes with output-state heterodyne measurements. We first derive analytical expressions for…

Quantum Physics · Physics 2020-12-29 Yong Siah Teo , Kimin Park , Seongwook Shin , Hyunseok Jeong , Petr Marek

We consider Gaussian states of fermionic systems and study the action of the partial transposition on the density matrix. It is shown that, with a suitable choice of basis, these states are transformed into a linear combination of two…

Statistical Mechanics · Physics 2015-05-29 Viktor Eisler , Zoltan Zimboras

The maximum amount of entanglement achievable under passive transformations by continuous-variable states is called the entanglement potential. Recent work has demonstrated that the entanglement potential is upper-bounded by a simple…

Quantum Physics · Physics 2023-07-24 Bohan Li , Aritra Das , Spyros Tserkis , Prineha Narang , Ping Koy Lam , Syed M. Assad

How to manage coherence as a continuous variable quantum resource is still an open question. We face this situation from the very definition of incoherent states in quadrature basis. We apply several measures of coherence for some physical…

Quantum Physics · Physics 2023-07-18 Laura Ares , Alfredo Luis

We investigate the role of quadrature squeezing in the quantum teleportation protocol for coherent states, using non-Gaussian resource states. For the two-mode systems, the non-Gaussian resource states that we use are obtained by an…

Quantum Physics · Physics 2025-02-25 Mohak Sharma , Chandan Kumar , Shikhar Arora , Arvind

It is known that general convertibility of bipartite entangled states is not possible to arbitrary error without some classical communication. While some trade-offs between communication cost and conversion error have been proven, these…

Quantum Physics · Physics 2024-10-15 Ian George , Eric Chitambar

The peculiar uncertainty or randomness of quantum measurements stems from coherence, whose information-theoretic characterization is currently under investigation. Under the resource theory of coherence, it is interesting to investigate…

Quantum Physics · Physics 2019-10-25 Xiao Yuan , Qi Zhao , Davide Girolami , Xiongfeng Ma

We study the energy current and its fluctuations in quantum gapless 1d systems far from equilibrium modeled by conformal field theory, where two separated halves are prepared at distinct temperatures and glued together at a point contact.…

Strongly Correlated Electrons · Physics 2012-08-29 Denis Bernard , Benjamin Doyon