Probing the quantum–classical connection with open quantum dots

Ferry, D. K.; Akis, R.; Brunner, Roland

doi:10.1088/0031-8949/2015/t165/014010

Cited by 8 publications

(7 citation statements)

References 44 publications

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“…One such open quantum system coupled to a complex environment is the open "quantum dot" in which coupling to the "dot" is by normal transport, and not by tunnelling. This system illustrates the complexities of the system/environment coupling, and has been the subject of several experimental (Bird et al, 1997(Bird et al, , 2003 and theoretical reviews (Ferry, Burke et al 2011, Brunner, Ferry et al 2012, Ferry, Akis et al 2015 The Coulomb blockade in ionic channels is closely related to this open quantum system. (Grabert and Devoret 1992, Kaufman, McClintock et al 2015, Feng, Liu et al 2016…”

Section: Particle and Displacement Currents In Quantum Systemsmentioning

confidence: 94%

Dynamics of Current, Charge and Mass

Eisenberg

Oriols

Ferry

2017

Computational and Mathematical Biophysics

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Electricity plays a special role in our lives and life. Equations of electron dynamics are nearly exact and apply from nuclear particles to stars. These Maxwell equations include a special term the displacement current (of vacuum). Displacement current allows electrical signals to propagate through space. Displacement current guarantees that current is exactly conserved from inside atoms to between stars, as long as current is defined as Maxwell did, as the entire source of the curl of the magnetic field. We show how the Bohm formulation of quantum mechanics allows easy definition of current. We show how conservation of current can be derived without mention of the polarization or dielectric properties of matter. Matter does not behave the way physicists of the 1800's thought it does with a single dielectric constant, a real positive number independent of everything. Charge moves in enormously complicated ways that cannot be described in that way, when studied on time scales important today for electronic technology and molecular biology. Life occurs in ionic solutions in which charge moves in response to forces not mentioned or described in the Maxwell equations, like convection and diffusion. Classical derivations of conservation of current involve classical treatments of dielectrics and polarization in nearly every textbook. Because real dielectrics do not behave in a classical way, classical derivations of conservation of current are often distrusted or even ignored. We show that current is conserved exactly in any material no matter how complex the dielectric, polarization or conduction currents are. We believe models, simulations, and computations should conserve current on all scales, as accurately as possible, because physics conserves current that way. We believe models will be much more successful if they conserve current at every level of resolution, the way physics does.Comment: Version 4 slight reformattin

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Section: Particle and Displacement Currents In Quantum Systemsmentioning

confidence: 94%

Dynamics of Current, Charge and Mass

Eisenberg

Oriols

Ferry

2017

Computational and Mathematical Biophysics

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“…The former is entropic in nature, while the latter, focused on the state structure, is geometric. Both frameworks have been studied in various spin-spin and spin-boson models [6][7][8][9][10][11][12][13][14][15][16][17][18][19], illuminated spheres [5,[20][21][22], quantum Brownian motion [23][24][25][26][27][28], single N -level environments [29,30], generalised probabilistic theories [31], and even in QED [32], gravitational [33], and experimental quantum-dot [34][35][36][37][38] and photonic [39] settings. Together, quantum Darwinism and spectrum broadcast structure have made important conceptual contributions to the long-standing problem of the quantum-to-classical transition.…”

mentioning

confidence: 99%

Strong Quantum Darwinism and Strong Independence are Equivalent to Spectrum Broadcast Structure

Le¹,

Olaya-Castro²

2019

Phys. Rev. Lett.

108

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How the objective everyday world emerges from the underlying quantum behaviour of its microscopic constituents is an open question at the heart of the foundations of quantum mechanics. Quantum Darwinism and spectrum broadcast structure are two different frameworks providing key insight into this question. Recent works, however, indicate these two frameworks can lead to conflicting predictions on the objectivity of the state of a system interacting with an environment. Here we provide a resolution to this issue by defining strong quantum Darwinism and proving that it is equivalent to spectrum broadcast structure when combined with strong independence of the subenvironments. We further show that strong quantum Darwinism is sufficient and necessary to signal state objectivity without the requirement of strong independence. Our work unveils the deep connection between strong quantum Darwinism and spectrum broadcast structure, thereby making fundamental progress towards understanding and solving the emergence of classicality from the quantum world. Together they provide us a sharper understanding of the transition in terms of state structure, geometry, and quantum and classical information.arXiv:1803.08936v2 [quant-ph]

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“…This term can be new processes depending upon both the environment and the system. One such type is the resonant back-scattering trajectories from quantum dots in a magnetic field [14][15][16], which depends critically upon the actual confinement structure of the device and its contacts. However, how does ρ D differ from ρ PD = Pρ D ?…”

Section: The Nature Of Complex Quantum Systemsmentioning

confidence: 99%

Complex Systems in Phase Space

Ferry

Nedjalkov

Weinbub

et al. 2020

Entropy

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The continued reduction of semiconductor device feature sizes towards the single-digit nanometer regime involves a variety of quantum effects. Modeling quantum effects in phase space in terms of the Wigner transport equation has evolved to be a very effective approach to describe such scaled down complex systems, accounting from full quantum processes to dissipation dominated transport regimes including transients. Here, we discuss the challanges, myths, and opportunities that arise in the study of these complex systems, and particularly the advantages of using phase space notions. The development of particle-based techniques for solving the transport equation and obtaining the Wigner function has led to efficient simulation approaches that couple well to the corresponding classical dynamics. One particular advantage is the ability to clearly illuminate the entanglement that can arise in the quantum system, thus allowing the direct observation of many quantum phenomena.

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Probing the quantum–classical connection with open quantum dots

Cited by 8 publications

References 44 publications

Dynamics of Current, Charge and Mass

Dynamics of Current, Charge and Mass

Strong Quantum Darwinism and Strong Independence are Equivalent to Spectrum Broadcast Structure

Complex Systems in Phase Space

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