Biomedical subjects

A Furusaki

Publications and source records attributed to A Furusaki.

At least 19 recordsLinked to original sources

PubMed2002

Occupation of a resonant level coupled to a chiral Luttinger liquid.

We consider a resonant level coupled to a chiral Luttinger liquid which can be realized, e.g., at a fractional quantum Hall edge. We study the dependence of the occupation probability n of the level on its energy epsilon for various values of the Luttinger-liquid parameter g. At g<1/2, a weakly coupled level shows a sharp jump in n(epsilon) at the Fermi level. As the coupling is increased, the magnitude of the jump decreases until sqrt[2g], and then the discontinuity in n(epsilon) disappears. We show that n(epsilon) can be expressed in terms of the magnetization of a Kondo impurity as a function of magnetic field.

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PubMed2002

Phase diagram of the one-dimensional extended Hubbard model at half filling.

We reexamine the ground-state phase diagram of the one-dimensional half-filled Hubbard model with on-site and nearest-neighbor repulsive interactions. We calculate second-order corrections to coupling constants in the weak-coupling renormalization-group approach ( g-ology) to show that the bond-charge-density-wave (BCDW) phase exists for weak couplings in between the charge-density-wave (CDW) and spin-density-wave (SDW) phases. We find that the umklapp scattering of parallel-spin electrons destabilizes the BCDW state and gives rise to a bicritical point where the CDW-BCDW and SDW-BCDW continuous-transition lines merge into the CDW-SDW first-order transition line.

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PubMed2000

Localization and delocalization in dirty superconducting wires

We present Fokker-Planck equations that describe transport of heat and spin in dirty unconventional superconducting quantum wires. Four symmetry classes are distinguished, depending on the presence or absence of time-reversal and spin-rotation invariance. In the absence of spin-rotation symmetry, heat transport is anomalous in that the mean conductance decays like 1/sqrt[L] instead of exponentially fast for large enough length L of the wire. The Fokker-Planck equations in the presence of time-reversal symmetry are solved exactly and the mean conductance for quasiparticle transport is calculated for the crossover from the diffusive to the localized regime.

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PubMed2000

Density of states in coupled chains with off-diagonal disorder

We compute the density of states rho(varepsilon) in N coupled chains with random hopping. At zero energy, rho(varepsilon) shows a singularity that strongly depends on the parity of N. For odd N, rho(varepsilon) approximately 1/|varepsilonln (3)varepsilon|, with and without time-reversal symmetry. For even N, rho(varepsilon) approximately |lnvarepsilon| in the presence of time-reversal symmetry, while there is a pseudogap, rho(varepsilon) approximately |varepsilonlnvarepsilon|, in the absence of time-reversal symmetry.

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PubMed1996