Persistent current and Drude weight in mesoscopic rings

Persistent current and Drude weight in mesoscopic rings

We study the persistent current and the Drude weight of a system of spinless fermions, with repulsive interactions and a hopping impurity, on a mesoscopic ring pierced by a magnetic flux, using a Density Matrix Renormalization Group algorithm for complex fields. Both the Luttinger Liquid (LL) and the Charge Density Wave (CDW) phases of the system are considered. Under a Jordan-Wigner transforma...

Persistent current and Drude weight in one-dimensional rings with substitution potentials

Persistent currents and Drude weights are investigated for the tight-binding approximation to one-dimensional rings threaded by a magnetic flux and with potential given by some almost-periodic substitution sequences with different degrees of randomness, and for various potential strengths. The Drude weight D distinguishes correctly conductors and insulators, in accordance with the results shown...

Persistent spin currents in mesoscopic Heisenberg rings.

We show that at low temperatures T an inhomogeneous radial magnetic field with magnitude B gives rise to a persistent magnetization current around a mesoscopic ferromagnetic Heisenberg ring. Under optimal conditions, this spin current can be as large as gmicro(B)(T/ variant Planck's over 2pi )exp([-2pi(gmicro(B)B/delta)(1/2)], as obtained from leading-order spin-wave theory. Here g is the gyrom...

Persistent currents in mesoscopic rings and conformal invariance

The effect of point defects on persistent currents in mesoscopic rings is studied in a simple tight-binding model. Using an analogy with the treatment of the critical quantum Ising chain with defects, conformal invariance techniques are employed to relate the persistent current amplitude to the Hamiltonian spectrum just above the Fermi energy. From this, the dependence of the current on the mag...

Quantum Transport: Persistent Current in Mesoscopic Loops