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Related papers: Generation of Coherence via Gaussian Measurements

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Quantum coherence quantifies the amount of superposition a quantum state can have in a given basis. Since there is a difference in the structure of eigenstates of the ergodic and many-body localized systems, we expect them also to differ in…

Strongly Correlated Electrons · Physics 2020-07-29 Sayandip Dhara , Alioscia Hamma , Eduardo R. Mucciolo

Quantum coherence has wide-ranging applications from quantum thermodynamics to quantum metrology, quantum channel discrimination and even quantum biology. Thus, detecting and quantifying coherence are two fundamental problems in quantum…

Quantum Physics · Physics 2021-03-30 Zhao Ma , Zhou Zhang , Yue Dai , Yuli Dong , Chengjie Zhang

The Gaussian states are essential ingredients in many tasks of quantum information processing. The presence of the noises imposes limitations on achieving these quantum protocols. Therefore, examining the evolution of quantum entanglement…

Quantum Physics · Physics 2022-07-27 Y. Lahlou , L. Baqmou , B. Maroufi , M. Daoud

The distribution of coherence in multipartite systems in examined. We use a new coherence measure with entropic nature and metric properties, based on the quantum Jensen-Shannon divergence. The metric property allows for the coherence to be…

Quantum Physics · Physics 2016-04-26 R. Chandrashekar , P. Manikandan , J. Segar , Tim Byrnes

Decoherence of a quantum system induced by the interaction with its environment (measuring medium) may be presented phenomenologically as a continuous (or repeated) fuzzy quantum measurement. The dynamics of the system subject to continuous…

Quantum Physics · Physics 2007-05-23 Michael B. Mensky

Measurements of quantum systems can be used to generate classical data that is truly unpredictable for every observer. However, this true randomness needs to be discriminated from randomness due to ignorance or lack of control of the…

Quantum Physics · Physics 2017-06-14 Felix Bischof , Hermann Kampermann , Dagmar Bruß

The transient dynamics of quantum coherence of Gaussian states are investigated. The state is coupled to an external environment which can be described by a Fano-Anderson type Hamiltonian. Solving the quantum Langevin equation, we obtain…

Quantum Physics · Physics 2022-01-20 Md. Manirul Ali , Chandrashekar Radhakrishnan

In this thesis we focus on Gaussian quantum metrology in the phase-space formalism and its applications in quantum sensing and the estimation of space-time parameters. We derive new formulae for the optimal estimation of multiple parameters…

Quantum Physics · Physics 2016-10-13 Dominik Šafránek

The interdependence of position and momentum, as highlighted by the Heisenberg uncertainty principle, is a cornerstone of quantum physics. Yet, position-momentum correlations have received little systematic attention. Motivated by recent…

Quantum Physics · Physics 2025-07-22 Varun Upreti , Ulysse Chabaud

We introduce a measurement-based method for verifying quantum discord of any bipartite quantum system. We show that by performing an informationally complete POVM (IC-POVM) on one subsystem and checking the commutativity of the conditional…

Quantum Physics · Physics 2013-01-23 Saleh Rahimi-Keshari , Carlton M. Caves , Timothy C. Ralph

The formation of multipartite quantum entanglement by repeated operation of one and two qubit gates is examined. The resulting entanglement is evaluated using two measures: the average bipartite entanglement and the Groverian measure. A…

Quantum Physics · Physics 2009-11-13 Yonatan Most , Yishai Shimoni , Ofer Biham

We present a detailed analytic framework for studying multimode non-Gaussian states that are conditionally generated when few modes of a multimode Gaussian state are subject to photon-number-resolving detectors. From the output state Wigner…

Quantum Physics · Physics 2019-04-22 Daiqin Su , Casey R. Myers , Krishna Kumar Sabapathy

A pair of quantum observables diagonal in the same "incoherent" basis can be measured jointly, so some coherence is obviously required for measurement incompatibility. Here we first observe that coherence in a single observable is linked to…

Quantum Physics · Physics 2022-01-11 Jukka Kiukas , Daniel McNulty , Juha-Pekka Pellonpää

We introduce a feasible protocol for generating non-Gaussian (nG) states via postselected von Neumann measurement for continuous-variable quantum information processing. The method uses a two-level system coupled to a Gaussian pointer state…

Quantum Physics · Physics 2025-10-01 Xiao-Xi Yao , Yusuf Turek

Quantum coherence, a basic feature of quantum mechanics residing in superpositions of quantum states, is a resource for quantum information processing. Coherence emerges in a fundamentally different way for nonidentical and identical…

We investigate the extent to which ``interaction-free'' measurements perturb the state of quantum systems. We show that the absence of energy exchange during the measurement is not a sufficient criterion to preserve that state, as the…

Quantum Physics · Physics 2009-11-06 S. Potting , E. S. Lee , W. Schmitt , I. Rumyantsev , B. Mohring , P. Meystre

In this work, we study the dynamics of quantum coherence (total coherence, global coherence and local coherence) evolving under a local PT-symmetric Hamiltonian in maximally entangled bipartite and tripartite states. Our results indicate…

Quantum Physics · Physics 2024-11-07 Akanksha Gautam , Kavita Dorai , Arvind

Quantum measurements necessarily disturb the state of physical system. Once we perform a complete measurement, the system undergoes decoherence and loses its coherence. If there is no disturbance, the state retains all of its coherence. It…

Quantum Physics · Physics 2018-10-10 Gautam Sharma , Arun Kumar Pati

We suggest a method to reconstruct the zero-delay-time second-order correlation function $g^{(2)}(0)$ of Gaussian states using a single homodyne detector. To this purpose, we have found an analytic expression of $g^{(2)}(0)$ for single- and…

Quantum Physics · Physics 2018-06-26 Stefano Olivares , Simone Cialdi , Matteo G. A. Paris

A measurement is deemed successful, if one can maximize the information gain by the measurement apparatus. Here, we ask if quantum coherence of the system imposes a limitation on the information gain during quantum measurement. First, we…

Quantum Physics · Physics 2020-04-02 Gautam Sharma , Sk Sazim , Arun Kumar Pati