Searcharxiv⌕ Search

arXiv subjects

Ken-ichiro Imura

Publications and source records attributed to Ken-ichiro Imura.

5 recordsLinked to original sources
arXiv1999

Tunneling into fractional quantum Hall liquids

Motivated by the recent experiment by Grayson et.al., we investigate a non-ohmic current-voltage characteristics for the tunneling into fractional quantum Hall liquids. We give a possible explanation for the experiment in terms of the chiral Tomonaga-Luttinger liquid theory. We study the interaction between the charge and neutral modes, and found that the leading order correction to the exponent $α$ $(I\sim V^α)$ is of the order of $\sqrtε$ $(ε=v_n/v_c)$, which reduces the exponent $α$. We suggest that it could explain the systematic discrepancy between the observed exponents and the exact $α=1/ν$ dependence.

cond-mat↗
arXiv1998

Tunneling in Paired Fractional Quantum Hall States: Conductance and Andreev Reflection of Non-Abelions

We study the edge transport properties of paired fractional quantum Hall (FQH) states--- the Haldane-Rezayi (HR), Moore-Read (Pfaffian) and Halperin (331) states. A table of exponents is given for the tunneling between the edges of paired FQH states in gated 2D structures and the tunneling into the edge of FQH states from a normal Fermi liquid (N). It is found that HR, Pfaffian and 331 states have different exponents for quasiparticle tunneling. For the tunneling through a FQH-N junction, we propose unusual Andreev reflection processes that may also probe the non-abelian FQH states.

cond-mat↗
arXiv1997

Effects of long-range Coulomb interaction on the quantum transport in fractional quantum Hall edges

We study the effects of long-range Coulomb interaction (LRCI) on the quantum transport in FQH edges with $ν=1/(2k+1)$. We consider two models, i.e., the quasi-particle tunneling (QPT) model and the electron tunneling (ET) model at the point contact. The tunneling conductance $G(T)$ is obtained using the renormalization group treatment. In QPT model, it is found that LRCI further reduces $G(T)$ below a crossover temperature $Λ_w$. In ET model, on the other hand, there is a temeperature region where LRCI enhances $G(T)$, and nonmonotonic temperature dependence is possible.

cond-mat↗
arXiv1997

Quantum transport in $ν=2/3$ spin-singlet quantum Hall edges

Tunneling conductance $G(T)$ through a constricted point contact is studied for the $ν=2/3$ spin-singlet edges. Including spin-flip tunneling, Zeeman splitting and random magnetic impurities, we discuss the various crossovers of $G(T)$ as a function of the temperature $T$. The behavior of $G(T)$ is found to be quite different for spin-singlet and spin-polarized cases, and hence $G(T)$ is expected to serve as an experimental probe for the polarized-unpolarized transition at $ν=2/3$.

cond-mat↗