TUNNELING FOR DIRAC FERMIONS IN CONSTANT MAGNETIC FIELD

2010 ◽  
Vol 07 (06) ◽  
pp. 909-931 ◽  
Author(s):  
EL BOUÂZZAOUI CHOUBABI ◽  
MOHAMED EL BOUZIANI ◽  
AHMED JELLAL
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Resonant Tunneling ◽  
Continuity Equation ◽  
Energy Gap ◽  
Tunneling Effect ◽  
Dirac Fermions ◽  
Two Dimensional ◽  
Transmission Coefficients ◽  
Total Transmission

The tunneling effect of two-dimensional Dirac fermions in a constant magnetic field is studied. This can be done by using the continuity equation at some points to determine the corresponding reflexion and transmission coefficients. For this, we consider a system made of graphene as superposition of two different regions where the second is characterized by an energy gap t'. In fact, we treat concrete systems to practically give two illustrations: barrier and diode. For each case, we discuss the transmission in terms of the ratio of the energy conservation and t'. Moreover, we analyze the resonant tunneling by introducing a scalar Lorentz potential where it is shown that a total transmission is possible.

scholarly journals NONCOMMUTATIVE GRAPHENE

2013 ◽  
Vol 28 (16) ◽  
pp. 1350064 ◽  
Author(s):  
CATARINA BASTOS ◽  
ORFEU BERTOLAMI ◽  
NUNO COSTA DIAS ◽  
JOÃO NUNO PRATA
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Dirac Equation ◽  
Energy Levels ◽  
Dirac Fermions ◽  
Two Dimensional ◽  
Dirac System ◽  
Noncommutative Parameter

We consider a noncommutative description of graphene. This description consists of a Dirac equation for massless Dirac fermions plus noncommutative corrections, which are treated in the presence of an external magnetic field. We argue that, being a two-dimensional Dirac system, graphene is particularly interesting to test noncommutativity. We find that momentum noncommutativity affects the energy levels of graphene and we obtain a bound for the momentum noncommutative parameter.

Highly accurate analytical energy of a two-dimensional exciton in a constant magnetic field

2016 ◽  
Vol 495 ◽  
pp. 16-20 ◽  
Author(s):  
Ngoc-Tram D. Hoang ◽  
Duy-Anh P. Nguyen ◽  
Van-Hung Hoang ◽  
Van-Hoang Le
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Two Dimensional

scholarly journals Confined Dirac fermions in a constant magnetic field

2009 ◽  
Vol 80 (1) ◽  
Author(s):  
Ahmed Jellal ◽  
Abdulaziz D. Alhaidari ◽  
Hocine Bahlouli
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Dirac Fermions

THE ENTANGLED QUANTUM HEAT ENGINE IN THE VARIOUS HEISENBERG MODELS FOR A TWO-QUBIT SYSTEM

2013 ◽  
Vol 11 (02) ◽  
pp. 1350021 ◽  
Author(s):  
ERHAN ALBAYRAK
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Heat Engine ◽  
Exchange Parameter ◽  
Thermodynamic Quantities ◽  
Two Dimensional ◽  
Quantum Heat Engine ◽  
Qubit System ◽  
Heisenberg Models ◽  
Different Temperatures

The four-level entangled quantum heat engine (QHE) is analyzed in the various Heisenberg models for a two-qubit. The QHE is examined for the XX, XXX and XXZ Heisenberg models by introducing a parameter x which controls the strength of the exchange parameter Jz = xJ along the z-axis with respect to the ones along the x- and y-axes, i.e. Jx = Jy = J, respectively. It is assumed that the two-qubit is entangled and in contact with two heat reservoirs at different temperatures and under the effect of a constant magnetic field. The concurrences (C) are used as a measure of entanglement and then the expressions for the amount of heat transferred, the work performed and the efficiency of the QHE are derived. The contour, i.e. the isoline maps, and some two-dimensional plots of the above mentioned thermodynamic quantities are calculated and some interesting features are found.

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