Biomedical subjects

Y Avishai

Publications and source records attributed to Y Avishai.

At least 19 recordsLinked to original sources

PubMed2001

Resonant electron transmission through a finite quantum spin chain.

Electron transport in a finite one-dimensional quantum spin chain (with ferromagnetic exchange) is studied within an s-d exchange Hamiltonian. Spin transfer coefficients strongly depend on the sign of the s-d exchange constant. For a ferromagnetic coupling, they exhibit a novel resonant pattern, reflecting the salient features of the combined electron-spin system. Spin-flip processes are inelastic and feasible at finite voltage or at finite temperature.

Journal Article↗

PubMed2001

Kondo tunneling through real and artificial molecules.

When an asymmetric double dot is hybridized with itinerant electrons, its singlet ground state and lowly excited triplet state cross, leading to a competition between the Zhang-Rice mechanism of singlet-triplet splitting in a confined cluster and the Kondo effect (which accompanies the tunneling through quantum dot under a Coulomb blockade restriction). The rich physics of an underscreened S = 1 Kondo impurity in the presence of low-lying triplet-singlet excitations is exposed and estimates of the magnetic susceptibility and the electric conductance are presented, together with applications for molecule chemisorption on metallic substrates.

Journal Article↗

PubMed2000

Quantum dots with even number of electrons: kondo effect in a finite magnetic field

We show that the Kondo effect can be induced by an external magnetic field in quantum dots with an even number of electrons. If the Zeeman energy B is close to the single-particle level spacing Delta in the dot, the scattering of the conduction electrons from the dot is dominated by an anisotropic exchange interaction. A Kondo resonance then occurs despite the fact that B exceeds by far the Kondo temperature T(K). As a result, at low temperatures T<<T(K) the differential conductance approaches a unitary limit G(K) approximately e(2)/piPlanck's over 2pi. A possible experimental realization of this effect is discussed.

Journal Article↗

PubMed1996