Two recent experiments [I. P. Radu et al., Science 320, 899 (2008) and X. Lin et al., Phys. Rev. B 85, 165321 (2012)] measured the temperature and voltage dependence of the quasiparticle tunneling through a quantum point contact in the ν= 5/2 quantum Hall liquid. The results led to conflicting conclusions about the nature of the quantum Hall state. In this paper, we show that the conflict can be resolved by recognizing different geometries of the devices in the experiments. We argue that in some of those geometries there is significant unscreened electrostatic interaction between the segments of the quantum Hall edge on the opposite sides of the point contact. Coulomb interaction affects the tunneling current. We compare experimental results with theoretical predictions for the Pfaffian, SU(2)_2, 331 and K=8 states and their particle-hole conjugates. After Coulomb corrections are taken into account, measurements in all geometries agree with the spin-polarized and spin-unpolarized Halperin 331 states.
Interlayer tunneling in double-layer quantum Hall pseudo-ferromagnets
我们发现,在双层量子霍尔态的层间隧穿I-V表现出丰富的行为,这取决于样品尺寸,电压长度尺度,电流屏蔽,无序和热长度的相对大小。对于弱隧穿,我们预测负微分电导的幂律形状跨越到一个尖锐的零偏置峰。面内磁场分裂该零偏置峰,从而导致在$V_B(B_{||})=2π\hbar v B_{||}d/eϕ_0$处的“导数”特征,这给出了对应于双层霍尔态的自发对称性破缺的Goldstone模式的色散的直接测量。
We examine the spectroscopic signatures of tunneling through a Kitaev quantum spin liquid (QSL) barrier in a number of experimentally relevant geometries. We combine contributions from elastic and inelastic tunneling processes and find that spin-flip scattering at the itinerant spinon modes gives rise to a gaped contribution to the tunneling conductance spectrum. We address the spectral modifications that arise in a magnetic field necessary to drive the candidate material $α$-RuCl$_3$ into a QSL phase, and we propose a lateral 1D tunnel junction as a viable setup in this regime. The characteri…
We present the electron tunneling transport and spectroscopic characters of a superconducting {\it Josephson} junction with a barrier of single anisotropic Kitaev quantum spin liquid (QSL) layer. We find that the dynamical spin correlation features are well reflected in the direct-current differential conductance $dI^{c}/dV$ of the single-particle tunneling, including the unique spin gap and dressed itinerant Majorana dispersive band, in addition to an energy shift $2Δ$ of two-lead superconducting gaps. From the spectral characters, we identify different topological quantum phases of the aniso…
The nature of the fractional quantum Hall state with filling factor $ν=2/3$ and its edge modes continues to remain an open problem in low-dimensional condensed matter physics. Here, we suggest an experimental setting to probe the $ν=2/3$ edge by tunnel-coupling it to a $ν=1$ integer quantum Hall edge in another layer of a two-dimensional electron gas (2DEG). In this double-layer geometry, the momentum of tunneling electrons may be boosted by an auxiliary magnetic field parallel to the two planes of 2DEGs. We evaluate the current as a function of bias voltage and the boosting magnetic field. It…
Anomalous charge tunneling in the fractional quantum Hall edge states at filling factor ν= 5/2
我们解释了最近在$ν=5/2$ [M. Dolev,Y.真恶心Y C. Chung,M. Heiblum,V. Umansky,and D. Mahalu,Phys.Rev. B. \textbf{81},161303(R)(2010)]。微分电导和过量噪声的实验数据进行拟合,使用反Pfronan模型,通过适当地考虑重整化的Luttinger参数诱导的耦合系统的固有$1/f$噪声。我们表明,一个奇特的凝聚物激发与电荷$e/2$,预期的$e/4$电荷的两倍,占主导地位的低能量下的输运性质。
Infrared catastrophe and tunneling into strongly correlated electron systems: Exact solution of the x-ray edge limit for the 1D electron gas and 2D Hall fluid
We theoretically investigate the tunneling spectroscopy of a system of two parallel one-dimensional helical conductors in the interacting, Luttinger liquid regime. We calculate the non-linear differential conductance as a function of the voltage bias between the conductors and the orbital momentum shift induced on tunneling electrons by an orthogonal magnetic field. We show that the conductance map exhibits an interference pattern which is characteristic to the interacting helical liquid. This can be contrasted with the different interference pattern from tunneling between regular Luttinger li…
Role of scaling dimensions in generalized noises in fractional quantum Hall tunneling due to a temperature bias
Chalmers University of Technology(查尔姆斯理工大学);Scuola Internazionale Superiore di Studi Avanzati(国际高等研究院);Beijing Academy of Quantum Information Sciences(北京量子信息科学研究院);Karlstad University(卡尔斯特大学)