共查询到20条相似文献,搜索用时 15 毫秒
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In a fractional quantum Hall system with a narrow constriction, tunneling of quasiparticles between states at different edges can lead to resistance and to shot noise. The ratio of the shot noise to the backscattered current, in the weak scattering regime, measures the fractional charge of the quasiparticle, which has been confirmed in several experiments. However, the predicted nonlinearity of the resistance was apparently not observed in some of these cases. As a possible explanation, we consider a model where coupling between the current carrying edge mode and additional phononlike edge modes can lead to nonuniversal exponents in the current-voltage characteristic. 相似文献
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We study the low-lying excitations of a quantum Hall sample that has undergone edge reconstruction such that there exist three branches of chiral edge excitations. Among the interaction processes that involve electrons close to the three Fermi points is a new type of Umklapp-scattering process which has not been discussed before. Using bosonization and a refermionization technique, we obtain exact results for electronic correlation functions and discuss the effect Umklapp scattering has on the Luttinger-liquid properties of quantum Hall edges. 相似文献
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《Physics letters. A》1987,124(8):450-452
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《Nuclear Physics B》1995,443(3):501-515
Starting from Laughlin-type wave functions with generalized periodic boundary conditions describing the degenerate ground state of a quantum Hall system we explicitly construct r-dimensional vector bundles. It turns out that the filling factor ν is given by the topological quantity c1/r where c1 is the first Chem number of these vector bundles. In addition, we managed to proof that under physical natural assumptions the stable vector bundles correspond to the experimentally dominating series of measured fractional filling factors ν = n/(2pn±1). Most remarkably, due to the very special form of the Laughlin wave functions the fluctuations of the curvature of these vector bundles converge to zero in the limit of infinitely many particles which shows a new mathematical property. Physically, this means that in this limit the Hall conductivity is independent of the boundary conditions which is very important for the observability of the effect. Finally, we discuss the relation of this result to a theorem of Donaldson. 相似文献
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Chyh-Hong Chern 《Annals of Physics》2007,322(10):2485-2492
We propose a pseudo-potential Hamiltonian for the Zhang-Hu’s generalized fractional quantum Hall states to be the exact and unique ground states. Analogously to Laughlin’s quasi-hole (quasi-particle), the excitations in the generalized fractional quantum Hall states are extended objects. They are vortex-like excitations with fractional charges +(−)1/m3 in the total configuration space CP3. The density correlation function of the Zhang-Hu states indicates that they are incompressible liquid. 相似文献
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Roddaro S Pellegrini V Beltram F Biasiol G Sorba L Raimondi R Vignale G 《Physical review letters》2003,90(4):046805
Remarkable nonlinearities in the differential tunneling conductance between fractional quantum Hall edge states at a constriction are observed in the weak-backscattering regime. In the nu=1/3 state a peak develops as temperature is increased and its width is determined by the fractional charge. In the range 2/3=nu=1/3 this width displays a symmetric behavior around nu=1/2. We discuss the consistency of these results with available theoretical predictions for interedge quasiparticle tunneling in the weak-backscattering regime. 相似文献
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P. Wiegmann 《Journal of Experimental and Theoretical Physics》2013,117(3):538-550
We propose a comprehensive framework for quantum hydrodynamics of the fractional quantum Hall (FQH) states. We suggest that the electronic fluid in the FQH regime can be phenomenologically described by the quantized hydrodynamics of vortices in an incompressible rotating liquid. We demonstrate that such hydrodynamics captures all major features of FQH states, including the subtle effect of the Lorentz shear stress. We present a consistent quantization of the hydrodynamics of an incompressible fluid, providing a powerful framework to study the FQH effect and superfluids. We obtain the quantum hydrodynamics of the vortex flow by quantizing the Kirchhoff equations for vortex dynamics. 相似文献
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The sharp
quantum Hall edge present for hard confinement is shown to have two modes that go soft as the confining potential softens. This signals a second order transition to a reconstructed edge that is either a depolarized spin-texture edge or a polarized charge density wave edge. 相似文献
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Ken-Ichiro Imura 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,15(1):155-160
Effects of backward scattering between fractional quantum Hall (FQH) edge modes are studied. Based on the edge-state picture
for hierarchical FQH liquids, we discuss the possibility of the transitions between different plateaux of the tunneling conductance
G. We find a selection rule for the sequence which begins with a conductance (m: integer, p: even integer) in units of e
2/h. The shot-noise spectrum as well as the scaling behavior of the tunneling current is calculated explicitly.
Received 5 October 1999 and Received in final form 19 November 1999 相似文献
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The fractional quantum Hall effect is studied in the 2D electron gas of four GaAs-AlxGa1?xAs heterostructures. Localization due to disorder, known to give rise to the wide integral quantum Hall plateaus, is demonstrated to inhibit the fractional effect, which is observed only in the higher mobility samples. 相似文献
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We have studied a clean finite-length line junction between interacting counterpropagating single-branch fractional quantum Hall edge channels. Exact solutions for low-lying excitations and transport properties are obtained when the two edges belong to quantum Hall systems with different filling factors and interact via the long-range Coulomb interaction. Charging effects due to the coupling to external edge-channel leads are fully taken into account. Conductances and power laws in the current-voltage characteristics of tunneling are strongly affected by interedge correlations. 相似文献
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