Related papers: Spin filtering through excited states in double qu…
Stimulated emission is a process during which an atomic system gives away energy to create a coherent photon. It is fundamental to the operation of the optical amplifier. Here we propose two mechanisms for amplifying AC spin currents in a…
We investigate coherent time-evolution of charge states (pseudo-spin qubit) in a semiconductor double quantum dot. This fully-tunable qubit is manipulated with a high-speed voltage pulse that controls the energy and decoherence of the…
For a double quantum dot system in a parallel geometry, we demonstrate that by combining the effects of a flux and driving an electrical current through the structure, the spin correlations between electrons localized in the dots can be…
We report measurements of spin transitions for GaAs quantum dots in the Coulomb blockade regime, and compare ground and excited state transport spectroscopy to direct measurements of the spin polarization of emitted current. Transport…
We consider a double quantum dot system with two embedded and non-aligned spin impurities to manipulate the magnitude and polarization of the electron spin density. The device is attached to semi-infinite one-dimensional leads which are…
We investigate the performance of dynamical decoupling methods at suppressing electron spin decoherence from a low-temperature nuclear spin reservoir in a quantum dot. The controlled dynamics is studied through exact numerical simulation,…
We present time-resolved measurements of spin-flip photon-assisted tunneling and spin-flip relaxation in a doubly occupied double quantum dot. The photon-assisted excitation rate as a function of magnetic field indicates that spin-orbit…
We propose a simple scheme for the spin filter by studying the coherent transport of electrons through a double-bend structure in a quantum wire with a weak lateral magnetic potential which is much weaker than the Fermi energy of the leads.…
We consider theoretically transport in a spinfull one-channel interacting quantum wire placed in an external magnetic field. For the case of two point-like impurities embedded in the wire, under a small voltage bias the spin-polarized…
We investigate spin and charge current through a quantum dot pumped by a time-varying magnetic field. Using the density matrix method, quantum rate equations for the electronic occupation numbers in the quantum dot are obtained and solved…
We analyze coherent spin phenomena in triple quantum dots in triangular configuration under crossed DC and AC magnetic fields. In particular, we discuss the interplay between Aharonov-Bohm current oscillations, coherent electron trapping…
We have investigated the transport characteristics of an electron pump consisting of an asymmetric double quantum dot at zero bias voltage which is subject to electromagnetic radiation. Depending on the energies of the intermediate states…
Quantum rings connected to ballistic circuits couple strongly to external magnetic fields if the connection is not symmetric. By analytical theory and computer simulation I show that properly connected rings can be used to pump currents in…
We analyze electron spin relaxation in electronic transport through coherently coupled double quantum dots in the spin blockade regime. In particular, we focus on hyperfine interaction as the spin relaxation mechanism. We pay special…
We show how realistic charge manipulation and measurement techniques, combined with the exchange interaction, allow for the robust generation and purification of four-particle spin entangled states in electrically controlled semiconductor…
We propose a spin-sensitive scanning probe microscopy experiment on double quantum dots in Pauli blockade conditions. Electric spin resonance is induced by an AC voltage applied to the scanning gate which induces lifting of the Pauli…
We propose a novel scheme to efficiently polarize and manipulate the electron spin in a quantum dot. This scheme is based on the spin-orbit interaction and it possesses following advantages: (1) The direction and the strength of the spin…
The spin filtering effect of the electron current in a double-barrier resonant-tunneling diode (RTD) consisting of ZnMnSe semimagnetic layers has been studied theoretically. The influence of the distribution of the magnesium ions on the…
We consider the full driven quantum dynamics of a qubit realized as spin of electron in a one-dimensional double quantum dot with spin-orbit coupling. The driving perturbation is taken in the form of a single half-period pulse of electric…
We demonstrate the operation of a quantum spin pump based on cyclic radio-frequency excitation of a GaAs quantum dot, including the ability to pump pure spin without pumping charge. The device takes advantage of bidirectional mesoscopic…