Related papers: Low temperature decoherence by electron-electron i…
We theoretically consider coherence times for spins in two quantum computer architectures, where the qubit is the spin of an electron bound to a P donor impurity in Si or within a GaAs quantum dot. We show that low temperature decoherence…
The performance of modern quantum devices in communication, metrology or microscopy relies on the quantum-classical interaction which is generally described by the theory of decoherence. Despite the high relevance for long coherence times…
We studied phase coherent phenomena in mesoscopic Permalloy samples by exploring low temperature transport. Both, differential conductance as a function of bias voltage and magnetoconductance of individual wires display conductance…
At temperatures $T < {\hbar v_F}/{K_B d} \equiv T^{wire}$ the collective excitations are negligible and the spectrum of the short wire is dominated by the ''zero modes'' particle excitations. At temperature $ T > T^{wire}$ a spin polarized…
The decoherence rate of a quantum dot coupled to a fluctuating environment described by a normal-metal superconductor junction is considered. The density-density correlator at low frequencies constitutes the kernel which enters the…
The conductance coefficients of disordered mesoscopic devices with $n$ probes are investigated within the noninteracting electron approximation at zero temperature. The probes are eliminated from the theoretical description at the expense…
The electron transport in a 1D conductor with an isolated local defect such as an impurity or a non-adiabatic contact is studied theoretically. New regime of conduction in correlated 1D systems is predicted beyond the well-known regime of…
Recent work on the temperature-driven delocalization in the quantum Hall regime is reviewed, with emphasis on the role of electron-electron interactions and the correlation properties of disorder. We have stressed (i) the crucial role of…
We investigate the effect of electron-electron interactions on the transport properties of disordered quasi one-dimensional quantum wires with two or more subbands occupied. We apply two alternative methods to solve the logarithmic…
The local density of states of a degenerate semiconductor is investigated at low magnetic fields. In order to realize this experiment, we designed a strongly asymmetric double-barrier heterostructure with heavily doped contacts and study…
In a recent paper, Phys. Rev. Lett. 81, 1074 (1998), Golubev and Zaikin (GZ) found that ``zero-point fluctuations of electrons'' contribute to the dephasing rate extracted from the magnetoresistance. As a result, the dephasing rate remains…
The controversy with respect to the role of electron-electron collisions in the dynamic conductivity of dense plasmas is resolved. In particular, the dc conductivity is analyzed in the low-density, non-degenerate limit where the Spitzer…
In Newtonian mechanics, any closed-system dynamics of a composite system in a microstate will leave all its individual subsystems in distinct microstates, however this fails dramatically in quantum mechanics due to the existence of quantum…
For the first time, new important features of the fluctuation electromagnetic interaction between a small conducting particle and a smooth surface of polarizable medium (both dielectric and metallic) are worked out. The particle is…
We study heat transfer mediated by near-field fluctuations of the electromagnetic field. In case of metals the latter are dominated by Coulomb interactions between thermal fluctuations of electronic density. We show that an elastic…
We report measurements of the electron dephasing time extracted from the weak localization (WL) correction to the average conductance in an open AlGaAs/GaAs quantum dot from 1 K to 13 mK. In agreement with theoretical predictions but in…
Quantum coherence of electrons in ferromagnetic metals is difficult to assess experimentally. We report the first measurements of time-dependent universal conductance fluctuations in ferromagnetic metal (Ni$_{0.8}$Fe$_{0.2}$) nanostructures…
We study the low-temperature critical behavior of the one-dimensional Hubbard model near half filling caused by enhanced antiferromagnetic fluctuations. We use a mean-field-type approximation with a two-particle self-consistency…
We consider a system of two-dimensional electrons strongly localized by disorder. Interactions create a gap in the average tunneling density of states $\nu(E)$ at energies, E, close to the Fermi level. We derive a system of self-consistent…
We consider a model of electrons at zero temperature, with a repulsive interaction which is a function of the energy transfer. Such an interaction can arise from the combination of electron-electron repulsion at high energies and the weaker…