scholarly journals Effects of Fermi energy, dot size, and leads width on weak localization in chaotic quantum dots

2001 ◽  
Vol 63 (11) ◽  
Author(s):  
E. Louis ◽  
J. A. Vergés
Keyword(s):  
Quantum Dots ◽  
Fermi Energy ◽  
Weak Localization

Weak localization in ballistic quantum dots

1999 ◽  
Vol 60 (4) ◽  
pp. 2680-2690 ◽  
Author(s):  
R. Akis ◽  
D. K. Ferry ◽  
J. P. Bird ◽  
D. Vasileska
Keyword(s):  
Quantum Dots ◽  
Weak Localization

scholarly journals Single-particle and collective excitations in quantum wires comprised of vertically stacked quantum dots: Finite magnetic field

2020 ◽  
Vol 34 (36) ◽  
pp. 2150173
Author(s):  
Manvir S. Kushwaha
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Quantum Computation ◽  
Dielectric Function ◽  
Single Particle ◽  
Fermi Energy ◽  
Quantum Wires ◽  
Random Phase ◽  
Collective Excitations ◽  
Stacked Quantum Dots

A theoretical investigation has been made of the magnetoplasmon excitations in a quasi-one-dimensional electron system composed of vertically stacked, self-assembled InAs/GaAs quantum dots. The smaller length scales involved in the experiments impel us to consider a perfectly periodic system of two-dimensionally confined InAs quantum dot layers separated by GaAs spacers. Subsequent system is subjected to a two-dimensional confining (harmonic) potential in the [Formula: see text]–[Formula: see text] plane and an applied magnetic field (B) in the symmetric gauge. This scheme defines virtually a system of quantum wire comprised of vertically stacked quantum dots (VSQD). We derive and discuss the Dyson equation, the generalized (nonlocal and dynamic) dielectric function, and the inverse dielectric function for investigating the single-particle and collective (magnetoplasmon) excitations within the framework of (full) random-phase approximation (RPA). As an application, we study the influence of the confinement potential and the magnetic field on the component eigenfunctions, the density of states (DOS), the Fermi energy, the collective excitations, and the inverse dielectric functions. How the B-dependence of DOS validate the VSQD mimicking the realistic quantum wires, the Fermi energy oscillates as a function of the Bloch vector, the intersubband single-particle continuum bifurcates at the origin, a collective excitation emerges and propagates within the gap of the split single-particle continuum, and the alteration in the well- and barrier-widths allows to customize the excitation spectrum in the desired energy range are some of the remarkable features of this investigation. These findings demonstrate, for the very first time, the significance of investigating the system of VSQD subjected to a quantizing magnetic field. Given the edge over the planar quantum dots and the foreseen applications in the single-electron devices and quantum computation, investigating the system of VSQD is deemed vital. The results suggest exploiting magnetoplasmon qubits to be a potential option for implementing the solemn idea of quantum state transfer in devising quantum gates for the quantum computation and quantum communication networks.

Condensed matter physics

2018 ◽  
Author(s):  
Yan Fyodorov ◽  
Dmitry Savin
Keyword(s):  
Quantum Dots ◽  
Shot Noise ◽  
Matrix Theory ◽  
Quantum Wires ◽  
Condensed Matter ◽  
Weak Localization ◽  
Scattering Matrix ◽  
Condensed Matter Physics ◽  
Conductance Fluctuations ◽  
Non Gaussian

This article discusses some applications of concepts from random matrix theory (RMT) to condensed matter physics, with emphasis on phenomena, predicted or explained by RMT, that have actually been observed in experiments on quantum wires and quantum dots. These observations range from universal conductance fluctuations (UCF) to weak localization, non-Gaussian thermopower distributions, and sub-Poissonian shot noise. The article first considers the UCF phenomenon, nonlogarithmic eigenvalue repulsion, and sub-Poissonian shot noise in quantum wires before analysing level and wave function statistics, scattering matrix ensembles, conductance distribution, and thermopower distribution in quantum dots. It also examines the effects (not yet observed) of superconductors on the statistics of the Hamiltonian and scattering matrix.

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