Quantized ν = 5/2 state in a two-subband quantum hall system.
نویسندگان
چکیده
The evolution of the fractional quantum Hall state at filling 5/2 is studied in density tunable two-dimensional electron systems formed in wide wells in which it is possible to induce a transition from single- to two-subband occupancy. In 80 and 60 nm wells, the quantum Hall state at 5/2 filling of the lowest subband is observed even when the second subband is occupied. In a 50 nm well, the 5/2 state vanishes upon second subband population. We attribute this distinct behavior to the width dependence of the capacitive energy for intersubband charge transfer and of the overlap of the subband probability densities.
منابع مشابه
The fractional quantum Hall effect in wide quantum wells
Currently, there is a strong interest in the even-denominator fractional quantum Hall state at filling factor ν = 5/2, observed in state-of-the-art GaAs based two-dimensional electron systems. This interest stems from the potential relevance of this ground state for topological quantum computation resulting from the non-Abelian statistics its quasi-particle excitations are predicted to obey. Pa...
متن کاملEvolution of the 7/2 fractional quantum Hall state in two-subband systems.
We report the evolution of the fractional quantum Hall state (FQHS) at a total Landau level (LL) filling factor of ν=7/2 in wide GaAs quantum wells in which electrons occupy two electric subbands. The data reveal subtle and distinct evolutions as a function of density, magnetic field tilt angle, or symmetry of the charge distribution. At intermediate tilt angles, for example, we observe a stren...
متن کاملFractional charge in the fractional quantum hall system
The fractional quantum Hall effect (FQHE) has uncovered a number of unique and unexpected quantum behaviors of two-dimensional electrons. For the integer quantum Hall effect (IQFE), the conductance of the bulk is quantized as σxy = n(e2/h) for integer n. This behaviors can be explained as the complete filling of a Landau level in the 2D free electron system with an external magnetic field. Sinc...
متن کامل53 v 1 3 F eb 2 00 0 Quantum - Critical Dynamics of the Skyrmion Lattice
Near to filling fraction ν = 1, the quantum Hall ferromagnet contains multiple Skyrmion spin excitations. This multi-Skyrmion system has a tremendously rich quantum-critical structure. This is simplified when Skyrmions are pinned by disorder. We calculate the nuclear relaxation rate in this case and compare the result with experiment. We discus how such measurements may be used to further probe...
متن کاملA numerical renormalization group approach for calculating the spectrum of a vibronic system occurring in molecules or impurities in insulators
Theoretically, in order to describe the behavior of a spectrum, a mathematical model whichcould predict the spectrum characteristics is needed. Since in this study a Two-state system has beenused like models which was introduced previously past and could couple with the environment, theformer ideas have been extended in this study. we use the second quantized version for writing thisHamiltonian...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 108 4 شماره
صفحات -
تاریخ انتشار 2012