Semiclassical Effects and Degree of Quantumness  

Specific Effects, Concepts, and Examples > s.a. classical mechanics [effective dynamics]; fluctuations; operators; phase transition; quantum information.
* Continuous spontaneous localization: In the GRW prescription, obtained with non-linear and stochastic effects.
@ Continuous spontaneous localization: Ghirardi et al PRD(86) [comment Joos PRD(87) + reply PRD(87)], FP(88); Benatti et al NCB(87) [and measurement]; Bell in(89); Ghirardi et al FP(90), PRA(90); Pearle PRA(93), in(97)qp/98.
@ Measurement and decoherence: Mensky PU(98)qp, qp/98-proc, 00; Furuta PRA(01) [model]; Bhattacharya et al PRA(03)qp/02; Zurek RMP(03); Ford et al PRA(01)qp/03; Schlosshauer RMP(04)qp/03 [and interpretations]; Ghose et al PRA(05)qp/04; > s.a. decoherence; types of measurement.
@ And the correspondence principle: Habib et al PRL(98) [non-linear dynamics]; Bernal et al a1101 [mathematical formulation, and harmonic oscillator].
@ Trajectories: Brun et al PLA(97); Greenbaum et al PRE(07)-a0705 [vs phase space distributions]; Nölle a1005 [geometric approach].
@ Measures: Fedichkin et al SPIE(03)cm.
@ Non-classical effects: Resch et al PRA(01) [in single-γ detection]; Sikivie & Todarello PLB(17)-a1607 [duration of classicality].
@ Examples: Brun et al PRL(03)qp/02, PRA(03)qp/02, PRA(03)qp/02 [random walk]; Man'ko et al PLA(05); Benet et al PRA(07)qp/06 [chemical reactions]; Jasiak et al NJP(09) [electrons in thin metal films]; Teta EJP(10)-a0905 [straight tracks in a cloud chamber]; news seed(09)jul [Caltech experiment]; Radonjić et al PRA(12) [quantum spin].
> Related topics: see locality; Loschmidt Echo; matter [stability]; quantum fields; quantum chaos; relativistic quantum theory; scattering; SQUIDs.
> States and simple models: see Baker's Map; coherent states; quantum states.
> Systems: see composite systems; ergodic systems; macroscopic systems; photons; quantum systems; spin models; spin systems.

blue bullet Related pages: see quantum state evolution; relationship classical-quantum theory; semiclassical limit; semiclassical states.

Quantum vs Classical States, Quantumness and Classicality > s.a. correlations [quantum discord]; quantum measurement.
* Measures / degree: Some notions used to quantify quantumness are contextuality and negativity of the Wigner function.
* Idea: Quantum states differ from classical ones in their localization, interference properties and entanglement; One way to check when a system will start to deviate from its classical behavior is to look for when the quantum Wigner function deviates from the corresponding classical phase-space probability density.
@ Quantum vs classical states: Loris & Sasaki PLA(04) [eigenvalues vs normal modes]; Yoder AJP(06)may [probability densities]; Hen & Kalev qp/07 [quantum states approaching classical distributions]; Kiesel et al PRA(08)-a0804 [based on Glauber-Sudarshan P-function]; Ellis AP(12)-a1108 [and contextuality]; Kiesel PRA(13)-a1303, Park et al PRL(15)-a1505 [in terms of phase-space distributions]; Egloff et al PRX(18) [framework]; > s.a. distances.
@ Quantumness and classicality: Anastopoulos PRD(99)qp/98; Hall PRA(00) [Fisher information]; Costa Dias JMP(02)qp/99; Malbouisson & Baseia PS(03)qp/02 [field theory]; Avelar et al qp/03; Zurek qp/03 [information and environment]; Alicki et al JPA(08) [quantumness witnesses]; Gehrke et al PRA(12)-a0904 [quantification]; Giraud et al NJP(10)-a1002; Zhu et al PLA(11)-a1010; Schmid & Duenki a1101; Tammaro FP(12)-a1110 [non-classical, non-quantum theories]; Kot et al PRL(12)-a1110 [breakdown of a classical description]; Fazio et al PRA(13)-a1201 [via anticommutators]; Steinhoff a1204; Facchi et al JPA(14)-a1309 [from algebra of observables]; Gittsovich et al PRA(15)-a1412 [macroscopic superposition states]; Reusch et al PRA(15)-a1501 [entanglement witnesses, indistinguishable particles]; Fresta et al PRA(15)-a1508; Bardet a1511 [classical and quantum parts of an environment]; Castrillón et al a1608 [for single systems]; Delfosse et al NJP(17)-a1610 [contextuality and negativity of the Wigner function]; Alexanian PRA(16)-a1610 [different criteria]; Bose a1701 [and non-Gaussianity, in terms of Wehrl entropy]; Tan et al a1906 [hierarchy of non-classicality measures]; Abbasli et al a2001 [degree of classicality, in quasiprobability representations]; Park et al a2005 [hierarchy of criteria in phase space]; Milz et al PRX(20) [non-Markovian processes]; > s.a. correlations; types of distances.
@ And entanglement: Everitt et al NJP(05); Groisman et al qp/07; Piani & Adesso PRA(12)-a1110; Facchi et al JPA(12)-a1111; Killoran et al PRL(16)-a1505.
@ For specific types of states / systems: Korbicz et al PRL(05)qp/04 [harmonic oscillator]; Girolami et al JPA(11)-a1008 [non-classical correlations for two-qubit mixed states]; Puri PRA(12)-a1410 [for a system of spin-1/2 particles]; Trapani et al PRA(15)-a1411 [oscillator + environment, dynamics of classicality]; Miranowicz et al PRA(15)-a1502 [single-qubit states]; Kumari & Ghose PRA(18)-a1802 [chaotic systems, near periodic orbits]; Marian & Marian a1909 [quantum optics].
@ Quantumness vs classicality tests: Alicki & Van Ryn JPA(08); Brida et al OE(08)-a0804; Luís PRA(10); Ferro et al EPJD(18)-a1501 [interferometric setup]; Hameedi et al a1511 [unconditional experimental test]; Marletto & Vedral a2003 [mediating the generation of entanglement].

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