Related papers: Coherent spin control by electromagnetic vacuum fl…
We investigate the coupling of the spin angular momentum of light beams with elliptical polarization to the spin degree of freedom of free electrons. It is shown that this coupling, which is of similar origin as the well-known spin-orbit…
I study the quantum mechanics of a spin interacting with an ``apparatus''. Although the evolution of the whole system is unitary, the spin evolution is not. The system is chosen so that the spin exhibits loss of quantum coherence, or…
The impact of control sequences on the environmental coupling of a quantum system can be described in terms of a filter. Here we analyze how the coherent evolution of two interacting spins subject to periodic control pulses, at the example…
Coherent dynamics of localized spins in semiconductors is limited by spectral diffusion arising from dipolar fluctuation of lattice nuclear spins. Here we extend the semiclassical theory of spectral diffusion for nuclear spins I=1/2 to the…
We compute correlation functions for one-dimensional electron systems which spin and charge degrees of freedom are coupled through spin-orbit coupling. Charge density waves, spin density waves, singlet- triplet- superconducting fluctuations…
Partially coherent light beams are encountered both in classical and in quantum optics. Their coherence properties generally depend on the correlation properties of their sources. In this paper, we propose a technique for controlling the…
Theoretical study is performed of a single-mode polariton system with linear coupling of spin components. When combined with an ordinary two-particle interaction, the spin coupling involves a spontaneous symmetry breaking accompanied by a…
We use the spin-polarized excitons in a single quantum dot to design optical controls for basic operations in quantum computing. We examine the ultrafast nonlinear optical processes required and use the coherent nonlinear optical responses…
In one dimension very general results from conformal field theory and exact calculations for certain quantum spin systems have established universal scaling properties of the entanglement entropy between two parts of a critical system.…
Fluctuations and noise may alter the behavior of dynamical systems considerably. For example, oscillations may be sustained by demographic fluctuations in biological systems where a stable fixed point is found in the absence of noise. We…
We describe the light-matter interaction of a single two level atom with the electromagnetic vacuum in terms of field and dipole variables by considering homodyne detection of the emitted fields. Spontaneous emission is then observed as a…
We show that nonequilibrium spin fluctuations significantly influence the electronic transport in a single-electron transistor, when the spin relaxation on the island is slow compared to other relaxation processes, and when size effects…
Nuclear spins of noble gases can maintain coherence for hours at ambient conditions owing to their extraordinary isolation by the enclosing, complete electronic shells. This isolation, however, impedes the ability to manipulate and control…
In spin systems, the decay of the Loschmidt echo in the time-reversal experiment (evolution, perturbation, time-reversed evolution) is linked to the generation of multiple-quantum coherences. The approach is extended to other systems, and…
We investigate beyond-mean-field dynamics in a fully connected $\mathrm{SU}(3)$ spin-exchange model, focusing on the interplay between chaotic dynamics and quantum fluctuations. Using the two-particle irreducible (2PI) effective action…
We consider a two-dimensional disordered conductor in the regime when the superconducting phase is destroyed by the magnetic field. We analyze a combination of fluctuations of different origin which results in an effective interaction…
We consider the decoherence of a pseudo-spin ensemble under collective random rotations, and study, both theoretically and experimentally, how a nondestructive measurement combined with real-time feedback correction can protect the state…
Quantum coherent control of bimolecular collisions beyond the ultracold regime can face a major challenge due to the incoherent addition of different partial wave contributions to the total scattering cross section. These contributions…
It is well-known that some nonlinear phenomena such as strong photon blockade are hard to be observed in optomechanical system with current experimental technology. Here, we present a coherent feedback control strategy in which a linear…
Coherent control is a method used to manipulate the state of matter using oscillatory electromagnetic radiation which relies on the non-adiabatic interaction. It is commonly applied in quantum processing applications. This technique is…