Special Issue "Symmetry and Mesoscopic Physics"

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Physics and Symmetry/Asymmetry".

Deadline for manuscript submissions: closed (15 February 2021).

Special Issue Editors

Prof. Dr. Vyacheslav Yukalov
E-Mail Website
Guest Editor
Bogolubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research, 141980 Dubna, Russia
Interests: optimized perturbation theory; self-similar approximation theory; method of self-similar prediction; correlated iteration theory; theory of heterophase fluctuations
Special Issues, Collections and Topics in MDPI journals
Dr. Rashid G. Nazmitdinov
E-Mail Website
Guest Editor
Bogolubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia
Interests: transport in nanostructures; graphene; random matrix approach; nuclear structure
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Symmetry is one of the most important notions in natural science. This notion lies at the heart of fundamental laws of nature and serves as an important tool for understanding the properties of complex systems, both classical and quantum.

The other trend, which has in recent years undergone intensive development, is mesoscopic physics. This branch of physics also combines classical and quantum ideas and methods. Two main directions can be distinguished in mesoscopic physics. One is the study of finite quantum systems of mesoscopic sizes. Such systems, which are between the atomic and macroscopic scales, exhibit a variety of novel phenomena and find numerous applications in creating modern electronic and spintronic devices. At the same time, the behavior of large systems can be influenced by mesoscopic effects, which provides another direction within the framework of mesoscopic physics.

The aim of the present Special Issue is to emphasize the phenomena that lie at the crossroads between the concept of symmetry and mesoscopic physics. For example, the role of symmetry becomes apparent in the interplay between order and chaos in the classical limit, suggesting the most probable realizations of quantum equilibrium configurations of finite systems. On the other hand, the manifestation of symmetries and symmetry breaking in finite quantum systems has some peculiarities compared to macroscopic samples.

We are soliciting contributions (research and review articles) covering a broad range of topics on symmetry and mesoscopic physics, including (though not limited to) the following:

interplay between regular and chaotic dynamics in finite systems

particles confined in effective potentials of different shapes

manifestation of symmetry in the spectra of collective excitations

mesoscopic effects in large systems

local symmetry breaking

competition between order, disorder, and symmetry

possible coexistence of different types of symmetry breaking

symmetries in nanoscience

applied problems focusing on the role of symmetry in nano- and mesoscopic devices

 Guest Editor

Dr. Vyacheslav Yukalov
Dr. Rashid G. Nazmitdinov
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Symmetry is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • interplay between regular and chaotic dynamics in finite systems
  • particles confined in effective potentials of different shapes
  • manifestation of symmetry in the spectra of collective excitations
  • mesoscopic effects in large systems
  • local symmetry breaking
  • competition between order, disorder, and symmetry possible coexistence of different types of symmetry breaking
  • symmetries in nanoscience
  • applied problems focusing on the role of symmetry in nano- and mesoscopic devices

Published Papers (10 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Article
Nonlinear Dynamics of Wave Packets in Tunnel-Coupled Harmonic-Oscillator Traps
Symmetry 2021, 13(3), 372; https://doi.org/10.3390/sym13030372 - 25 Feb 2021
Cited by 1 | Viewed by 563
Abstract
We consider a two-component linearly coupled system with the intrinsic cubic nonlinearity and the harmonic-oscillator (HO) confining potential. The system models binary settings in BEC and optics. In the symmetric system, with the HO trap acting in both components, we consider Josephson oscillations [...] Read more.
We consider a two-component linearly coupled system with the intrinsic cubic nonlinearity and the harmonic-oscillator (HO) confining potential. The system models binary settings in BEC and optics. In the symmetric system, with the HO trap acting in both components, we consider Josephson oscillations (JO) initiated by an input in the form of the HO’s ground state (GS) or dipole mode (DM), placed in one component. With the increase of the strength of the self-focusing nonlinearity, spontaneous symmetry breaking (SSB) between the components takes place in the dynamical JO state. Under still stronger nonlinearity, the regular JO initiated by the GS input carries over into a chaotic dynamical state. For the DM input, the chaotization happens at smaller powers than for the GS, which is followed by SSB at a slightly stronger nonlinearity. In the system with the defocusing nonlinearity, SSB does not take place, and dynamical chaos occurs in a small area of the parameter space. In the asymmetric half-trapped system, with the HO potential applied to a single component, we first focus on the spectrum of confined binary modes in the linearized system. The spectrum is found analytically in the limits of weak and strong inter-component coupling, and numerically in the general case. Under the action of the coupling, the existence region of the confined modes shrinks for GSs and expands for DMs. In the full nonlinear system, the existence region for confined modes is identified in the numerical form. They are constructed too by means of the Thomas–Fermi approximation, in the case of the defocusing nonlinearity. Lastly, particular (non-generic) exact analytical solutions for confined modes, including vortices, in one- and two-dimensional asymmetric linearized systems are found. They represent bound states in the continuum. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Kramers Degeneracy and Spin Inversion in a Lateral Quantum Dot
Symmetry 2020, 12(12), 2043; https://doi.org/10.3390/sym12122043 - 10 Dec 2020
Viewed by 1223
Abstract
We show that the axial symmetry of the Bychkov–Rashba interaction can be exploited to produce electron spin-flip in a circular quantum dot, without lifting the time reversal symmetry. In order to elucidate this effect, we consider ballistic electron transmission through a two-dimensional circular [...] Read more.
We show that the axial symmetry of the Bychkov–Rashba interaction can be exploited to produce electron spin-flip in a circular quantum dot, without lifting the time reversal symmetry. In order to elucidate this effect, we consider ballistic electron transmission through a two-dimensional circular billiard coupled to two one-dimensional electrodes. Using the tight-binding approximation, we derive the scattering matrix and the effective Hamiltonian for the considered system. Within this approach, we found the conditions for the optimal realization of this effect in the transport properties of the quantum dot. Numerical analysis of the system, extended to the case of two-dimensional electrodes, confirms our findings. The relatively strong quantization of the quantum dot can make this effect robust against the temperature effects. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
On Symmetry Properties of The Corrugated Graphene System
Symmetry 2020, 12(4), 533; https://doi.org/10.3390/sym12040533 - 03 Apr 2020
Cited by 1 | Viewed by 1094
Abstract
The properties of the ballistic electron transport through a corrugated graphene system are analysed from the symmetry point of view. The corrugated system is modelled by a curved surface (an arc of a circle) connected from both sides to flat sheets. The spin–orbit [...] Read more.
The properties of the ballistic electron transport through a corrugated graphene system are analysed from the symmetry point of view. The corrugated system is modelled by a curved surface (an arc of a circle) connected from both sides to flat sheets. The spin–orbit couplings, induced by the curvature, give rise to equivalence between the transmission (reflection) probabilities of the transmitted (reflected) electrons with the opposite spin polarisation, incoming from opposite system sides. We find two integrals of motion that explain the chiral electron transport in the considered system. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Modulational Instability, Inter-Component Asymmetry, and Formation of Quantum Droplets in One-Dimensional Binary Bose Gases
Symmetry 2020, 12(1), 174; https://doi.org/10.3390/sym12010174 - 18 Jan 2020
Cited by 17 | Viewed by 1385
Abstract
Quantum droplets are ultradilute liquid states that emerge from the competitive interplay of two Hamiltonian terms, the mean-field energy and beyond-mean-field correction, in a weakly interacting binary Bose gas. We relate the formation of droplets in symmetric and asymmetric two-component one-dimensional boson systems [...] Read more.
Quantum droplets are ultradilute liquid states that emerge from the competitive interplay of two Hamiltonian terms, the mean-field energy and beyond-mean-field correction, in a weakly interacting binary Bose gas. We relate the formation of droplets in symmetric and asymmetric two-component one-dimensional boson systems to the modulational instability of a spatially uniform state driven by the beyond-mean-field term. Asymmetry between the components may be caused by their unequal populations or unequal intra-component interaction strengths. Stability of both symmetric and asymmetric droplets is investigated. Robustness of the symmetric solutions against symmetry-breaking perturbations is confirmed. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Small-Angle Scattering from Fractals: Differentiating between Various Types of Structures
Symmetry 2020, 12(1), 65; https://doi.org/10.3390/sym12010065 - 01 Jan 2020
Cited by 7 | Viewed by 988
Abstract
Small-angle scattering (SAS; X-rays, neutrons, light) is being increasingly used to better understand the structure of fractal-based materials and to describe their interaction at nano- and micro-scales. To this aim, several minimalist yet specific theoretical models which exploit the fractal symmetry have been [...] Read more.
Small-angle scattering (SAS; X-rays, neutrons, light) is being increasingly used to better understand the structure of fractal-based materials and to describe their interaction at nano- and micro-scales. To this aim, several minimalist yet specific theoretical models which exploit the fractal symmetry have been developed to extract additional information from SAS data. Although this problem can be solved exactly for many particular fractal structures, due to the intrinsic limitations of the SAS method, the inverse scattering problem, i.e., determination of the fractal structure from the intensity curve, is ill-posed. However, fractals can be divided into various classes, not necessarily disjointed, with the most common being random, deterministic, mass, surface, pore, fat and multifractals. Each class has its own imprint on the scattering intensity, and although one cannot uniquely identify the structure of a fractal based solely on SAS data, one can differentiate between various classes to which they belong. This has important practical applications in correlating their structural properties with physical ones. The article reviews SAS from several fractal models with an emphasis on describing which information can be extracted from each class, and how this can be performed experimentally. To illustrate this procedure and to validate the theoretical models, numerical simulations based on Monte Carlo methods are performed. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Metal–Insulator Transition in Three-Dimensional Semiconductors
Symmetry 2019, 11(11), 1345; https://doi.org/10.3390/sym11111345 - 01 Nov 2019
Viewed by 651
Abstract
We use a random gap model to describe a metal–insulator transition in three-dimensional semiconductors due to doping, and find a conventional phase transition, where the effective scattering rate is the order parameter. Spontaneous symmetry breaking results in metallic behavior, whereas the insulating regime [...] Read more.
We use a random gap model to describe a metal–insulator transition in three-dimensional semiconductors due to doping, and find a conventional phase transition, where the effective scattering rate is the order parameter. Spontaneous symmetry breaking results in metallic behavior, whereas the insulating regime is characterized by the absence of spontaneous symmetry breaking. The transition is continuous for the average conductivity with critical exponent equal to 1. Away from the critical point, the exponent is roughly 0.6, which may explain experimental observations of a crossover of the exponent from 1 to 0.5 by going away from the critical point. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Analysis of a Trapped Bose–Einstein Condensate in Terms of Position, Momentum, and Angular-Momentum Variance
Symmetry 2019, 11(11), 1344; https://doi.org/10.3390/sym11111344 - 01 Nov 2019
Cited by 9 | Viewed by 1898
Abstract
We analyze, analytically and numerically, the position, momentum, and in particular the angular-momentum variance of a Bose–Einstein condensate (BEC) trapped in a two-dimensional anisotropic trap for static and dynamic scenarios. Explicitly, we study the ground state of the anisotropic harmonic-interaction model in two [...] Read more.
We analyze, analytically and numerically, the position, momentum, and in particular the angular-momentum variance of a Bose–Einstein condensate (BEC) trapped in a two-dimensional anisotropic trap for static and dynamic scenarios. Explicitly, we study the ground state of the anisotropic harmonic-interaction model in two spatial dimensions analytically and the out-of-equilibrium dynamics of repulsive bosons in tilted two-dimensional annuli numerically accurately by using the multiconfigurational time-dependent Hartree for bosons method. The differences between the variances at the mean-field level, which are attributed to the shape of the BEC, and the variances at the many-body level, which incorporate depletion, are used to characterize position, momentum, and angular-momentum correlations in the BEC for finite systems and at the limit of an infinite number of particles where the bosons are 100 % condensed. Finally, we also explore inter-connections between the variances. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Symmetry Breaking in Stochastic Dynamics and Turbulence
Symmetry 2019, 11(10), 1193; https://doi.org/10.3390/sym11101193 - 23 Sep 2019
Cited by 2 | Viewed by 1113
Abstract
Symmetries play paramount roles in dynamics of physical systems. All theories of quantum physics and microworld including the fundamental Standard Model are constructed on the basis of symmetry principles. In classical physics, the importance and weight of these principles are the same as [...] Read more.
Symmetries play paramount roles in dynamics of physical systems. All theories of quantum physics and microworld including the fundamental Standard Model are constructed on the basis of symmetry principles. In classical physics, the importance and weight of these principles are the same as in quantum physics: dynamics of complex nonlinear statistical systems is straightforwardly dictated by their symmetry or its breaking, as we demonstrate on the example of developed (magneto)hydrodynamic turbulence and the related theoretical models. To simplify the problem, unbounded models are commonly used. However, turbulence is a mesoscopic phenomenon and the size of the system must be taken into account. It turns out that influence of outer length of turbulence is significant and can lead to intermittency. More precisely, we analyze the connection of phenomena such as behavior of statistical correlations of observable quantities, anomalous scaling, and generation of magnetic field by hydrodynamic fluctuations with symmetries such as Galilean symmetry, isotropy, spatial parity and their violation and finite size of the system. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Structural Properties of Vicsek-like Deterministic Multifractals
Symmetry 2019, 11(6), 806; https://doi.org/10.3390/sym11060806 - 18 Jun 2019
Cited by 5 | Viewed by 1033
Abstract
Deterministic nano-fractal structures have recently emerged, displaying huge potential for the fabrication of complex materials with predefined physical properties and functionalities. Exploiting the structural properties of fractals, such as symmetry and self-similarity, could greatly extend the applicability of such materials. Analyses of small-angle [...] Read more.
Deterministic nano-fractal structures have recently emerged, displaying huge potential for the fabrication of complex materials with predefined physical properties and functionalities. Exploiting the structural properties of fractals, such as symmetry and self-similarity, could greatly extend the applicability of such materials. Analyses of small-angle scattering (SAS) curves from deterministic fractal models with a single scaling factor have allowed the obtaining of valuable fractal properties but they are insufficient to describe non-uniform structures with rich scaling properties such as fractals with multiple scaling factors. To extract additional information about this class of fractal structures we performed an analysis of multifractal spectra and SAS intensity of a representative fractal model with two scaling factors—termed Vicsek-like fractal. We observed that the box-counting fractal dimension in multifractal spectra coincide with the scattering exponent of SAS curves in mass-fractal regions. Our analyses further revealed transitions from heterogeneous to homogeneous structures accompanied by changes from short to long-range mass-fractal regions. These transitions are explained in terms of the relative values of the scaling factors. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Show Figures

Figure 1

Article
Particle Fluctuations in Mesoscopic Bose Systems
Symmetry 2019, 11(5), 603; https://doi.org/10.3390/sym11050603 - 01 May 2019
Cited by 4 | Viewed by 980
Abstract
Particle fluctuations in mesoscopic Bose systems of arbitrary spatial dimensionality are considered. Both ideal Bose gases and interacting Bose systems are studied in the regions above the Bose–Einstein condensation temperature T c , as well as below this temperature. The strength of particle [...] Read more.
Particle fluctuations in mesoscopic Bose systems of arbitrary spatial dimensionality are considered. Both ideal Bose gases and interacting Bose systems are studied in the regions above the Bose–Einstein condensation temperature T c , as well as below this temperature. The strength of particle fluctuations defines whether the system is stable or not. Stability conditions depend on the spatial dimensionality d and on the confining dimension D of the system. The consideration shows that mesoscopic systems, experiencing Bose–Einstein condensation, are stable when: (i) ideal Bose gas is confined in a rectangular box of spatial dimension d > 2 above T c and in a box of d > 4 below T c ; (ii) ideal Bose gas is confined in a power-law trap of a confining dimension D > 2 above T c and of a confining dimension D > 4 below T c ; (iii) the interacting Bose system is confined in a rectangular box of dimension d > 2 above T c , while below T c , particle interactions stabilize the Bose-condensed system, making it stable for d = 3 ; (iv) nonlocal interactions diminish the condensation temperature, as compared with the fluctuations in a system with contact interactions. Full article
(This article belongs to the Special Issue Symmetry and Mesoscopic Physics)
Back to TopTop