Lower bounds for quantum energy levels through statistical mechanics methods

1980 ◽  
Vol 21 (4) ◽  
pp. 834-839 ◽  
Author(s):  
L. Nitti ◽  
M. Pellicoro ◽  
M. Villani
Keyword(s):  
Statistical Mechanics ◽  
Lower Bounds ◽  
Energy Levels ◽  
Quantum Energy

QUANTUM EFFECTS OF A DOMAIN WALL IN THE FERROMAGNETIC SYSTEM

2011 ◽  
Vol 25 (06) ◽  
pp. 413-418
Author(s):  
JI-SUO WANG ◽  
KE-ZHU YAN ◽  
BAO-LONG LIANG
Keyword(s):  
Domain Wall ◽  
Unitary Transformation ◽  
Energy Levels ◽  
Canonical Quantization ◽  
Classical Equation ◽  
Quantization Method ◽  
Damping Term ◽  
Quantum Energy ◽  
Moving Wall ◽  
Ferromagnetic System

Starting from the classical equation of the motion of a domain wall in the ferromagnetic systems, the quantum energy levels of the wall and the corresponding eigenfunctions in the case of considering damping term are given by using the canonical quantization method and unitary transformation. The quantum fluctuations of displacement and momentum of the moving wall has also been given as well as the uncertain relation.

Energy spectrum and wavefunction of electrons in hybrid superconducting nanowires

2016 ◽  
Vol 30 (13) ◽  
pp. 1642008 ◽  
Author(s):  
S. P. Kruchinin
Keyword(s):  
Energy Spectrum ◽  
Energy Levels ◽  
Superconducting Nanowires ◽  
Quantum Energy ◽  
Close Proximity ◽  
Superconducting Nanowire

Recent experiments have fabricated structured arrays. We study hybrid nanowires, in which normal and superconducting regions are in close proximity, by using the Bogoliubov–de Gennes equations for superconductivity in a cylindrical nanowire. We succeed to obtain the quantum energy levels and wavefunctions of a superconducting nanowire. The obtained spectra of electrons remind Hofstadter’s butterfly.

Calculation of spectral determinants

1994 ◽  
Vol 447 (1930) ◽  
pp. 413-437 ◽  
Keyword(s):  
Periodic Orbit ◽  
Finite Number ◽  
Dirichlet Series ◽  
Energy Levels ◽  
Euler Product ◽  
Quantum Energy ◽  
Type Formula

A method for regularizing spectral determinants is developed which facilitates their computation from a finite number of eigenvalues. This is used to calcu­late the determinant ∆ for the hyperbola billiard over a range which includes 46 quantum energy levels. The result is compared with semiclassical periodic orbit evaluations of ∆ using the Dirichlet series, Euler product, and a Riemann-Siegel-type formula. It is found that the Riemann-Siegel-type expansion, which uses the least number of orbits, gives the closest approximation. This provides explicit numerical support for recent conjectures concerning the analytic proper­ties of semiclassical formulae, and in particular for the existence of resummation relations connecting long and short pseudo-orbits.

Quantum states in a nanotube quantum dot

2017 ◽  
Vol 31 (25) ◽  
pp. 1745023
Author(s):  
J. T. Wang ◽  
J. D. Fan
Keyword(s):  
Carbon Nanotube ◽  
High Efficiency ◽  
Energy Levels ◽  
Quantum States ◽  
Semiconductor Surface ◽  
Energy Structure ◽  
Two Dimensional ◽  
Quantum Energy ◽  
Quantum Bit ◽  
Computer Chips

In this paper, we carry out a theoretical calculation of quantum state and quantum energy structure in carbon nanotube embedded semiconductor surface. In this theoretical model, the electrons in the carbon nanotube are considered as in a two-dimensional cylindrical surface. Their motion, therefore, can be described by the Dirac equation. We solve the equation and find that the energy levels are quantized and are linearly dependent on the wave vectors along the [Formula: see text]-direction that is along the direction of the nanotube. This type of energy structure may have potential application for fabricating high efficiency solar cell or quantum bit in computer chips.

scholarly journals A Note on the Warmth of Random Graphs with Given Expected Degrees

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Yilun Shang
Keyword(s):  
Statistical Mechanics ◽  
Chromatic Number ◽  
Random Graph ◽  
Lower Bounds ◽  
Random Graphs ◽  
Upper Bound ◽  
Degree Sequence ◽  
Graph Model ◽  
Upper And Lower Bounds ◽  
Random Graph Model

We consider the random graph modelG(w)for a given expected degree sequencew=(w1,w2,…,wn). Warmth, introduced by Brightwell and Winkler in the context of combinatorial statistical mechanics, is a graph parameter related to lower bounds of chromatic number. We present new upper and lower bounds on warmth ofG(w). In particular, the minimum expected degree turns out to be an upper bound of warmth when it tends to infinity and the maximum expected degreem=O(nα)with0<α<1/2.

Sweep rate effects and quantum energy levels in Josephson junctions

1990 ◽  
Vol 165-166 ◽  
pp. 947-948
Author(s):  
Paolo Silvestrini ◽  
Luigi Frunzio ◽  
Roberto Cristiano
Keyword(s):  
Josephson Junctions ◽  
Energy Levels ◽  
Sweep Rate ◽  
Quantum Energy ◽  
Rate Effects

The influence of classical resonances on quantum energy levels

1993 ◽  
Vol 99 (5) ◽  
pp. 3659-3668 ◽  
Author(s):  
B. Ramachandran ◽  
Kenneth G. Kay
Keyword(s):  
Energy Levels ◽  
Quantum Energy

Statistical mechanics and the partitions of numbers

1946 ◽  
Vol 42 (3) ◽  
pp. 272-277 ◽  
Author(s):  
F. C. Auluck ◽  
D. S. Kothari
Keyword(s):  
Statistical Mechanics ◽  
Heavy Nucleus ◽  
Asymptotic Expression ◽  
Energy Levels ◽  
Harmonic Oscillators ◽  
Partition Functions ◽  
Subsequent Paper ◽  
Interacting Particles ◽  
Bose Einstein ◽  
Positive Integers

1. The properties of partitions of numbers extensively investigated by Hardy and Ramanujan (1) have proved to be of outstanding mathematical interest. The first physical application known to us of the Hardy-Ramanujan asymptotic expression for the number of possible ways any integer can be written as the sum of smaller positive integers is due to Bohr and Kalckar (2) for estimating the density of energy levels for a heavy nucleus. The present paper is concerned with the study of thermodynamical assemblies corresponding to the partition functions familiar in the theory of numbers. Such a discussion is not only of intrinsic interest, but it also leads to some properties of partition functions, which, we believe, have not been explicitly noticed before. Here we shall only consider an assembly of identical (Bose-Einstein, and Fermi-Dirac) linear simple-harmonic oscillators. The discussion will be extended to assemblies of non-interacting particles in a subsequent paper.

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