اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدEffective mass suppression upon complete spin-polarization in an isotropic two-dimensional electron system
163
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We measure the effective mass (m*) of interacting two-dimensional electrons confined to a 4.5 nm-wide AlAs quantum well. The electrons in this well occupy a single out-of-plane conduction band valley with an isotropic in-plane Fermi contour. When the electrons are partially spin polarized, m* is larger than its band value and increases as the density is reduced. However, as the system is driven to full spin-polarization via the application of a strong parallel magnetic field, m* is suppressed down to values near or even below the band mass. Our results are consistent with the previously reported measurements on wide AlAs quantum wells where the electrons occupy an in-plane valley with an anisotropic Fermi contour and effective mass, and suggest that the effective mass suppression upon complete spin polarization is a genuine property of interacting two-dimensional electrons.
قيم البحث
اقرأ أيضاً
We present numerical calculations of the electron effective mass in an interacting, ferromagnetic, two-dimensional electron system. We consider quantum interaction effects associated with the charge-density fluctuation induced many-body vertex correc
tions. Our theory, which is free of adjustable parameters, reveals that the effective mass is suppressed (relative to its band value) in the strong coupling limit, in good agreement with the results of recent experimental measurements.
We report direct measurements of the valley susceptibility, the change of valley population in response to applied symmetry-breaking strain, in an AlAs two-dimensional electron system. As the two-dimensional density is reduced, the valley susceptibil
ity dramatically increases relative to its band value, reflecting the systems strong electron-electron interaction. The increase has a remarkable resemblance to the enhancement of the spin susceptibility and establishes the analogy between the spin and valley degrees of freedom.
A magnetotransport study in magnetically doped (Cd,Mn)Te 2D quantum wells reveals an apparent metal-insulator transition as well as an anomalous intermediate phase just on its metallic side. This phase is characterized by colossal magnetoresistance-l
ike phenomena, which are assigned to the phase separation of the electron fluid and the associated emergence of ferromagnetic bubbles.
A Dirac electron system in solids mimics a relativistic quantum physics that is compatible with Maxwells equations, by which we anticipate unified electromagnetic responses. We find a large orbital diamagnetism only along the interplane direction and
the nearly temperature-independent conductance of the order of e2/h for the new 2D Dirac organic conductor, a-(BETS)2I3. Distinct from conventional electrons in solids whose nonrelativistic effects bifurcate electric and magnetic responses, the observed orbital diamagnetism scales the electrical conductivity for a wide temperature range. This demonstrates that an electromagnetic duality that is valid only within the relativistic framework is revived in solids.
Current-induced spin polarization (CISP) is rederived in ballistic spin-orbit-coupled electron systems, based on equilibrium statistical mechanics. A simple and useful picture is correspondingly proposed to help understand the CISP and predict the po
larization direction. Nonequilibrium Landauer-Keldysh formalism is applied to demonstrate the validity of the statistical picture, taking the linear Rashba-Dresselhaus [001] two-dimensional system as a specific example. Spin densities induced by the CISP in semiconductor heterostructures and in metallic surface states are compared, showing that the CISP increases with the spin splitting strength and hence suggesting that the CISP should be more observable on metal and semimetal surfaces due to the discovered strong Rashba splitting. An application of the CISP designed to generate a spin-Hall pattern in the inplane, instead of the out-of-plane, component is also proposed.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
