Related papers: Nuclear Spin Switch in Semiconductor Quantum Dots

Without resorting to spin-spin coupling, we propose a scalable spin quantum computing scheme assisted with a semiconductor multiple-quantum-dot structure. The techniques of single electron transitions and the nanostructure of quantum-dot…

We demonstrate an alternative nuclear spin resonance using radio frequency (RF) electric field (nuclear electric resonance: NER) instead of magnetic field. The NER is based on the electronic control of electron spins forming a domain…

We develop a theory for spin transport and magnetization dynamics in a quantum-dot spin valve, i.e., two magnetic reservoirs coupled to a quantum dot. Our theory is able to take into account effects of strong correlations. We demonstrate…

We exploit the nonlinearity arising from the spin-photon interaction in an InAs quantum dot to demonstrate phase shifts of scattered light pulses at the single-photon level. Photon phase shifts of close to 90 degrees are achieved using a…

Molecular nanostructures are promising building blocks for future quantum technologies, provided methods of harnessing their multiple degrees of freedom can be identified and implemented. Due to low decoherence rates nuclear spins are…

Resonant optical excitation of lowest-energy excitonic transitions in self-assembled quantum dots lead to nuclear spin polarization that is qualitatively different from the well known optical orientation phenomena. By carrying out a…

We theoretically investigate the dynamical nuclear spin polarization in a quantum point contact (QPC) at finite magnetic field. We find that when the QPC is tuned to be spin selective, at the conductance of e^2/h, a finite bias induces a…

We demonstrate that efficient optical pumping of nuclear spins in semiconductor quantum dots (QDs) can be achieved by resonant pumping of optically "forbidden" transitions. This process corresponds to one-to-one conversion of a photon…

Molecular nanostructures may constitute the fabric of future quantum technologies, if their degrees of freedom can be fully harnessed. Ideally one might use nuclear spins as low-decoherence qubits and optical excitations for fast…

At the spin transition point of $\nu=2/3$ quantum Hall states, nuclear spins in a two-dimensional electron gas are polarized by an electric current. Using GaAs/AlGaAs double-quantum-well samples, we first observed the spatial diffusion of…

Due to their long coherence times, nuclear spins have gained considerable attention as physical qubits. Two-qubit gates between nuclear spins of distinct resonance frequencies can be mediated by electron spins, usually employing a sequence…

We investigate nuclear spin effects in a two-dimensional electron gas in the quantum Hall regime modeled by a weakly coupled array of interacting quantum wires. We show that the presence of hyperfine interaction between electron and nuclear…

We observe mixing between two-electron singlet and triplet states in a double quantum dot, caused by interactions with nuclear spins in the host semiconductor. This mixing is suppressed by applying a small magnetic field, or by increasing…

Nuclear spin polarization can be pumped into spin-blocked quantum dots by multiple Landau- Zener passages through singlet-triplet anticrossings. By numerical simulations of realistic systems including approximately $10^7$ nuclear spins…

The use of nuclear spins for quantum computation is limited by the difficulty in creating genuine quantum entanglement between distant nuclei. Current demonstrations of nuclear entanglement in semiconductors rely upon coupling the nuclei to…

We consider a new quantum gate mechanism based on electron spins in coupled semiconductor quantum dots. Such gates provide a general source of spin entanglement and can be used for quantum computers. We determine the exchange coupling J in…

We present a quantum mechanical theory of optically induced dynamic nuclear polarization applicable to quantum dots and other interacting spin systems. The exact steady state of the optically driven coupled electron-nuclear system is…

We present an approach for entangling electron spin qubits localized on spatially separated impurity atoms or quantum dots via a multi-electron, two-level quantum dot. The effective exchange interaction mediated by the dot can be understood…

We show theoretically that a strongly spin-polarized current can be generated in semiconductors by taking advantage of the ferromagnetic phase of a quantum dot array (QDA). A Hubbard model with coupling to leads is used to study the…

We present a theory and experiment demonstrating optical readout of charge and spin in a single InAs/GaAs self-assembled quantum dot. By applying a magnetic field we create the filling factor 2 quantum Hall singlet phase of the charged…