ترغب بنشر مسار تعليمي؟ اضغط هنا

Non-Commutativity effects in the Dirac equation in crossed electric and magnetic fields

85   0   0.0 ( 0 )
 نشر من قبل Orlando Panella
 تاريخ النشر 2018
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

In this paper we present exact solutions of the Dirac equation on the non-commutative plane in the presence of crossed electric and magnetic fields. In the standard commutative plane such a system is known to exhibit contraction of Landau levels when the electric field approaches a critical value. In the present case we find exact solutions in terms of the non-commutative parameters $eta$ (momentum non-commutativity) and $theta$ (coordinate non-commutativity) and provide an explicit expression for the Landau levels. We show that non-commutativity preserves the collapse of the spectrum. We provide a dual description of the system: (i) one in which at a given electric field the magnetic field is varied and the other (ii) in which at a given magnetic field the electric field is varied. In the former case we find that momentum non-commutativity ($eta$) splits the critical magnetic field into two critical fields while coordinates non-commutativity ($theta$) gives rise to two additional critical points not at all present in the commutative scenario.



قيم البحث

اقرأ أيضاً

362 - D. Nath , P. Roy 2017
We obtain solutions of the (2 + 1) dimensional k deformed Dirac equation in the presence of crossed magnetic and electric fields. It is shown that the k deformed Landau levels are modified in the presence of the electric field. Contraction of Landau levels has also been examined and it has been shown that the contraction depends on a critical magnetic field which is independent of the deformation parameter in first order approximation.
Quantum oscillations of nonlinear resistance are investigated in response to electric current and magnetic field applied perpendicular to single GaAs quantum wells with two populated subbands. At small magnetic fields current-induced oscillations app ear as Landau-Zener transitions between Landau levels inside the lowest subband. Period of these oscillations is proportional to the magnetic field. At high magnetic fields different kind of quantum oscillations emerges with a period,which is independent of the magnetic field. At a fixed current the oscillations are periodic in inverse magnetic field with a period that is independent of the dc bias. The proposed model considers these oscillations as a result of spatial variations of the energy separation between two subbands induced by the electric current.
50 - T. Bartsch , J. Main , G. Wunner 2002
The S-matrix theory formulation of closed-orbit theory recently proposed by Granger and Greene is extended to atoms in crossed electric and magnetic fields. We then present a semiclassical quantization of the hydrogen atom in crossed fields, which su cceeds in resolving individual lines in the spectrum, but is restricted to the strongest lines of each n-manifold. By means of a detailed semiclassical analysis of the quantum spectrum, we demonstrate that it is the abundance of bifurcations of closed orbits that precludes the resolution of finer details. They necessitate the inclusion of uniform semiclassical approximations into the quantization process. Uniform approximations for the generic types of closed-orbit bifurcation are derived, and a general method for including them in a high-resolution semiclassical quantization is devised.
The longitudinal resistivity of two dimensional (2D) electrons placed in strong magnetic field is significantly reduced by applied electric field, an effect which is studied in a broad range of magnetic fields and temperatures in GaAs quantum wells w ith high electron density. The data are found to be in good agreement with theory, considering the strong nonlinearity of the resistivity as result of non-uniform spectral diffusion of the 2D electrons. Inelastic processes limit the diffusion. Comparison with the theory yields the inelastic scattering time of the two dimensional electrons. In the temperature range T=2-10(K) for overlapping Landau levels, the inelastic scattering rate is found to be proportional to T^2, indicating a dominant contribution of the electron-electron scattering to the inelastic relaxation. In a strong magnetic field, the nonlinear resistivity demonstrates scaling behavior, indicating a specific regime of electron heating of well-separated Landau levels. In this regime the inelastic scattering rate is found to be proportional to T^3, suggesting the electron-phonon scattering as the dominant mechanism of the inelastic relaxation.
Oscillations of dissipative resistance of two-dimensional electrons in GaAs quantum wells are observed in response to an electric current I and a strong magnetic field applied perpendicular to the two-dimensional systems. Period of the current-induce d oscillations does not depend on the magnetic field and temperature. At a fixed current the oscillations are periodic in inverse magnetic fields with a period that does not depend on dc bias. The proposed model considers spatial variations of electron filling factor, which are induced by the electric current, as the origin of the resistance oscillations.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا