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Related papers: Correlations in atomic systems: Diagnosing coheren…

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We study emerging notions of quantum correlations in compound systems. Based on different definitions of quantumness in individual subsystems, we investigate how they extend to the joint description of a composite system. Especially, we…

Quantum Physics · Physics 2017-06-12 J. Sperling , E. Agudelo , I. A. Walmsley , W. Vogel

Quantum coherence is important in quantum mechanics, and its essence is from superposition principle. We study the coherence of any two pure states and that of their arbitrary superposition, and obtain the relationship between them. In the…

Quantum Physics · Physics 2016-05-25 Qiu-Ling Yue , Chao-Hua Yu , Feng Liu , Xiao-Li Wang , Fei Gao , Qiao-Yan Wen

The entanglement of multi-atom quantum states is considered. In order to cancel noise due to inhomogeneous light atom coupling, the concept of matched multi-atom observables is proposed. As a means to eliminate an important form of…

Quantum Physics · Physics 2009-11-10 A. Kuzmich , T. A. B. Kennedy

Interferometric photon-correlation measurements, which correspond to the second-order intensity cross-correlations between the two output ports of an unbalanced Michelson interferometer, are sensitive to both amplitude and phase…

Optics · Physics 2015-06-15 A. Lebreton , I. Abram , R. Braive , I. Sagnes , I. Robert-Philip , A. Beveratos

Quantum sensing exploits quantum phenomena to enhance the detection and estimation of classical parameters of physical systems and biological entities, particularly so as to overcome the inefficiencies of its classical counterparts. A…

Measures are introduced to quantify the degree of superposition in mixed states with respect to orthogonal decompositions of the Hilbert space of a quantum system. These superposition measures can be regarded as analogues to entanglement…

Quantum Physics · Physics 2007-05-23 Johan Aberg

Correlations are important tools in the characterization of quantum fields. They can be used to describe statistical properties of the fields, such as bunching and anti-bunching, as well as to perform field state tomography. Here we analyse…

Quantum Physics · Physics 2010-12-07 Marcus P. da Silva , Deniz Bozyigit , Andreas Wallraff , Alexandre Blais

Using coherent states in optical quantum process tomography is a practically-relevant approach. Here, we develop a framework for complete characterization of quantum-optical processes in terms of normally-ordered moments by using coherent…

Quantum Physics · Physics 2017-04-11 M. Ghalaii , A. T. Rezakhani

Multiplicity correlation measurements provide insight into the dynamics of high energy collisions. Models describing these collisions need these correlation measurements to tune the strengths of the underlying QCD processes which influence…

Nuclear Experiment · Physics 2016-04-27 K. Gulbrandsen , C. Soegaard

We propose a simple method for measuring the populations and the relative phase in a coherent superposition of two atomic states. The method is based on coupling the two states to a third common (excited) state by means of two laser pulses,…

Quantum Physics · Physics 2009-10-31 N. V. Vitanov , B. W. Shore , R. G. Unanyan , K. Bergmann

Light and matter share fundamental statistical properties, yet the experimental probes of quantum optics and many-body physics have largely evolved along separate trajectories. While many-body physics explores emergent collective phenomena,…

Correlations between spacelike separated measurements on entangled quantum systems are stronger than any classical correlations and are at the heart of numerous quantum technologies. In practice, however, spacelike separation is often not…

Quantum Physics · Physics 2017-11-28 Martin Ringbauer , Rafael Chaves

The specific advance of this work is to propose a mechanism by which superpositions collapse during measurement of the separated subsystems of entangled quantum states. It is shown how the phase that locks together entangled states plays a…

Quantum Physics · Physics 2026-05-20 Gregory D. Scholes

We study the correlations of classical and quantum systems from the information theoretical points of view. We analyze a simple measure of correlations based on entropy (such measure was already investigated as the degree of entanglement by…

Quantum Physics · Physics 2012-09-13 Yuji Hirota , Dariusz Chruściński , Takashi Matsuoka , Masanori Ohya

The manifestation of entanglement within geometric phase is elucidated for spatially-structured bi-photons. Entanglement parameters are shown to influence holonomy in two distinct ways: through statistical superpositions of separable…

Quantum Physics · Physics 2024-10-21 Mark T. Lusk

Quantum field theory is completely characterized by the field correlations between spacetime points. In turn, some of these can be accessed by locally coupling to the field simple quantum systems, a.k.a. particle detectors. In this work, we…

In this Letter, the quantum correlation measurement technique as a method of power noise monitoring is investigated. Its principal idea of correlating two photodetector signals is introduced and contrasted to the conventional approach,…

Optics · Physics 2022-03-02 Jasper Robert Venneberg , Benno Willke

We suggest measuring one-particle density matrix of a trapped ultracold atomic cloud by scattering fast atoms in a pure momentum state off the cloud. The lowest-order probability of the inelastic process, resulting in a pair of outcoming…

Soft Condensed Matter · Physics 2009-10-31 A. B. Kuklov , B. V. Svistunov

Developing superior quantum sensing strategies ranging from ultra-high precision measurement to complex structural analysis is at the heart of quantum technologies. While strategies using quantum resources, such as entanglement among…

Technologies for manipulating single atoms have advanced drastically in the past decades. Due to their excellent controllability of internal states, atoms serve as one of the ideal platforms as quantum systems. One major research direction…

Atomic Physics · Physics 2026-01-01 Akio Kawasaki