1,379 research outputs found
Quantum computing based on space states without charge transfer
An implementation of a quantum computer based on space states in double
quantum dots is discussed. There is no charge transfer in qubits during
calculation, therefore, uncontrollable entan-glement between them due to
long-range Coulomb interaction is suppressed. Other plausible sources of
decoherence caused by interaction with phonons and gates could be substantially
suppressed in the structure too. We also demonstrate how all necessary quantum
logic operations, initialization, writing, and read-out could be carried out in
the computer.Comment: 7 pages, 4 figures, RevTeX forma
Spintronics-based mesoscopic heat engine
We consider a nanowire suspended on two spin-polarized leads and subject to a
nonuniform magnetic field. We show that in such a system a temperature drop
between leads can significantly affect the nanowire dynamics. In particular, it
is demonstrated that under certain conditions the stationary distribution of
the mechanical subsystem has Boltzmann form with effective temperature which is
smaller than the temperature of the "cold" lead; this seems rather
counterintuitive. We also find that the change of the direction of the
temperature gradient results in generation of mechanical vibrations rather than
heating of the mechanical subsystem.Comment: 5 pages, 3 figure
On Properties of the Isoscalar Giant Dipole Resonance
Main properties (strength function, energy-dependent transition density,
branching ratios for direct nucleon decay) of the isoscalar giant dipole
resonance in several medium-heavy mass spherical nuclei are described within a
continuum-RPA approach, taking into account the smearing effect. All model
parameters used in the calculations are taken from independent data.
Calculation results are compared with available experimental data.Comment: 12 pages, 2 figure
Decay Properties Of The Dipole Isobaric Analog Resonances
A continuum-RPA-based approach is applied to describe the decay properties of
isolated dipole isobaric analog resonances in nuclei having not-too-large
neutron excess. Calculated for a few resonances in 90Zr the elastic
E1-radiative width and partial proton widths for decay into one-hole states of
89Y are compared with available experimental data.Comment: 8 pages, 4 figures, prepared with RevTe
Superconducting single-mode contact as a microwave-activated quantum interferometer
The dynamics of a superconducting quantum point contact biased at subgap
voltages is shown to be strongly affected by a microwave electromagnetic field.
Interference among a sequence of temporally localized, microwave-induced
Landau-Zener transitions between current carrying Andreev levels results in
energy absorption and in an increase of the subgap current by several orders of
magnitude. The contact is an interferometer in the sense that the current is an
oscillatory function of the inverse bias voltage. Possible applications to
Andreev-level spectroscopy and microwave detection are discussed
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