相关论文: Coherence in magnetic quantum tunneling
We discuss the charge and the spin tunneling currents between two Bardeen-Cooper-Schrieffer (BCS) superconductors, where one density of states is spin-split. In the presence of a large temperature bias across the junction, we predict the…
We formulate quantum tunneling as a time-of-arrival problem: we determine the detection probability for particles passing through a barrier at a detector located a distance L from the tunneling region. For this purpose, we use a…
For the realisation of scalable solid-state quantum-bit systems, spins in semiconductor quantum dots are promising candidates. A key requirement for quantum logic operations is a sufficiently long coherence time of the spin system.…
The observation of spin-dependent transport through organic chiral structures has sparked numerous fundamental and applicative questions ranging from biology to spintronics. By now, there is a broad consensus that the effect results from…
Phase slips are topological fluctuation events that carry the superconducting order-parameter field between distinct current carrying states. Owing to these phase slips low-dimensional superconductors acquire electrical resistance. In…
We solve Schr\"odinger equation describing a tunneling macrospin coupled to a torsional oscillator. Energy spectrum is studied for various quantum regimes. Magnetic susceptibility and noise spectrum are computed. We show that entanglement…
The principle of microscopic reversibility is a fundamental element in the formulation of fluctuation relations and the Onsager reciprocal relations. As such, a clear description of whether and how this principle is adapted to the quantum…
Tunneling is a fascinating aspect of quantum mechanics that renders the local minima of a potential meta-stable, with important consequences for particle physics, for the early hot stage of the universe, and more speculatively, for the…
We address the temperature influence on the precessional motion of electron spins under transverse magnetic field, studied in a GaAs/AlGaAs triple quantum wells, using pump-probe Kerr rotation. In the presence of an applied in-plane…
This paper considers two sets of formulas related to a Spin Coherence Time (SCT) case with only vertical oscillations in a purely electric ring, the first derived by the author for the field index m > 0 and the second by Ivan Koop for the…
We introduce a coherence susceptibility method, based on the fact that it signals quantum fluctuations, for identifying quantum phase transitions, which are induced by quantum fluctuations. This method requires no prior knowledge of order…
Electron tunneling in ferromagnetic single-electron transistors is considered theoretically in the sequential tunneling regime. A new formalism is developed, which operates in a two-dimensional space of states, instead of one-dimensiona…
Heat transport in spin-boson systems near the thermal equilibrium is systematically investigated. An asymptotically exact expression for the thermal conductance in a low-temperature regime wherein transport is described via a co-tunneling…
We consider a model for electron tunneling between a pair of ultrasmall metallic grains. Under appropriate circumstances, non-equilibrium final state effects can strongly enhance tunneling and produce electron-hole coherence between the…
The electromagnetic characteristics of bilayer quantum Hall systems in the presence of interlayer coherence and tunneling are studied by means of a pseudospin-texture effective theory and an algebraic framework of the single-mode…
We consider a periodic Ising chain with nearest-neighbour and $r$-th neighbour interaction and quench it from infinite temperature to zero temperature. The persistence probability $P(t)$, measured as the probability that a spin remains…
Spin precession of channelled particles in bent crystals at the LHC gives unique possibility for measurements as electric and magnetic moments of charm, beauty and strange charged baryons so and constants determining CP ($T_{odd}, P_{odd}$)…
The effect of the inevitable coupling to external degrees of freedom of a quantum computer are examined. It is found that for quantum calculations (in which the maintenance of coherence over a large number of states is important), not only…
We present a mechamism why interlayer tunneling conductivity in coherent bilayer quantum Hall states at $\nu=1$ is anomalously large, but finite in the recent experiment. According to the mechanism, pseudoSkyrmions causes the finite…
We describe the mechanism of charge-spin transformation in a double quantum dot (DQD) with even occupation, where a time dependent gate voltage v(t) is applied to one of its two valleys, whereas the other one is coupled to the source and…