اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدNumerical Calculation of the Neutral Fermion Gap at $ u=5/2$
244
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We present the first numerical computation of the neutral fermion gap, $Delta_psi$, in the $ u=5/2$ quantum Hall state, which is analogous to the energy gap for a Bogoliubov-de Gennes quasiparticle in a superconductor. We find $Delta_psi approx 0.027 frac{e^2}{epsilon ell_0}$, comparable to the charge gap, and discuss the implications for topological quantum information processing. We also deduce an effective Fermi velocity $v_F$ for neutral fermions from the low-energy spectra for odd numbers of electrons, and thereby obtain a correlation length $xi_{psi}={v_F}/Delta_{psi} approx 1.3, ell_0$. We comment on the implications of our results for electronic mechanisms of superconductivity more generally.
قيم البحث
اقرأ أيضاً
A modest in-plane magnetic field Bpar is sufficient to destroy the fractional quantized Hall states at $ u = 5/2$ and 7/2 and replace them with anisotropic compressible phases. Remarkably, we find that at larger Bpar these anisotropic phases can them
selves be replaced by isotropic compressible phases reminiscent of the composite fermion fluid at $ u = 1/2$. We present strong evidence that this transition is a consequence of the mixing of Landau levels from different electric subbands. We also report surprising dependences of the energy gaps at $ u = 5/2$ and 7/3 on the width of the confinement potential.
We report a reliable method to estimate the disorder broadening parameter from the scaling of the gaps of the even and major odd denominator fractional quantum Hall states of the second Landau level. We apply this technique to several samples of vast
ly different densities and grown in different MBE chambers. Excellent agreement is found between the estimated intrinsic and numerically obtained energy gaps for the $ u=5/2$ fractional quantum Hall state. Futhermore, we quantify, for the first time, the dependence of the intrinsic gap at $ u=5/2$ on Landau level mixing.
We investigate the finite frequency noise of a quantum point contact at filling factor { u} = 5/2 using a weakly coupled resonant LC circuit as a detector. We show how one could spectroscopically address the fractional charged excitations inspecting
separately their charge and scaling dimensions. We thus compare the behaviour of the Pfaffian and the anti-Pfaffian non-Abelian edge states models in order to give possible experimental signatures to identify the appropriate model for this fractional quantum Hall states. Finally we investigate how the temperature of the LC resonant circuit can be used in order to enhance the sensibility of the measurement scheme.
We propose an experiment to identify the topological order of the $ u=frac{5}{2}$ state through a measurement of the electric conductance of a mesoscopic device. Our setup is based on interfacing $ u=2, frac{5}{2}$ and $3$ in the same device. Its co
nductance can unambiguously establish or rule out the particle-hole symmetric Pfaffian topological order, which is supported by recent thermal measurements. Additionally, it distinguishes between the Moore-Read and Anti-Pfaffian topological orders, which are favored by numerical calculations.
We report on the dramatic evolution of the quantum Hall ferromagnet in the fractional quantum Hall regime at $ u = 2/5$ filling. A large enhancement in the characteristic timescale gives rise to a dynamical transition into a novel quantized Hall stat
e. The observed Hall state is determined to be a zero-temperature phase distinct from the spin-polarized and spin-unpolarized $ u = 2/5$ fractional quantum Hall states. It is characterized by a strong temperature dependence and puzzling correlation between temperature and time.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
