Related papers: Dynamic Nuclear Polarization in Double Quantum Dot…
We theoretically study the dynamic polarization of lattice nuclear spins in GaAs double quantum dots containing two electrons. In our prior work [Phys. Rev. Lett. 104, 226807 (2010)] we identified three regimes of long-term dynamics,…
We polarize nuclear spins in a GaAs double quantum dot by controlling two-electron spin states near the anti-crossing of the singlet (S) and m_S=+1 triplet (T+) using pulsed gates. An initialized S state is cyclically brought into resonance…
We observe multiple stable states of nuclear polarization in a double quantum dot under conditions of electron spin resonance. The stable states can be understood within an elaborated theoretical rate equation model for the polarization in…
We observe dynamic nuclear polarization in a GaAs double dot system using two electrons that are never exchanged with the reservoir. By periodically bringing the system to the mixing point where the singlet and the triplet T+ states are…
We proposed and demonstrated that the nuclear spins of the host lattice in GaAs double quantum dots can be strongly polarized in either of two opposite directions, parallel or antiparallel to an external magnetic field. The direction is…
A dynamical nuclear polarization scheme is studied in gated double dots. We demonstrate that a small polarization ($\sim 0.5%$) is sufficient to enhance the singlet decay time by two orders of magnitude. This enhancement is attributed to an…
We report on the dynamic nuclear polarization of a single charge-tunable self-assembled InAs/GaAs quantum dot in a longitudinal magnetic field of $\sim$0.2T. The hyperfine interaction between the optically oriented electron and nuclei spins…
We propose a new mechanism for polarizing nuclear spins in quantum dots, based on periodic modulation of the hyperfine coupling by electric driving at the electron spin resonance frequency. Dynamical nuclear polarization results from…
We theoretically investigate dynamic nuclear spin polarization in a self-assembled quantum dot pumped optically by two laser beams. With the assumption that a noncollinear interaction between the hole spin and nuclear spins leads to nuclear…
Transport through spin-blockaded quantum dots provides a means for electrical control and detection of nuclear spin dynamics in the host material. Although such experiments have become increasingly popular in recent years, interpretation of…
We investigate the dynamic nuclear polarization process by frequently injecting polarized electron spins into a quantum dot. Due to the suppression of the direct dipolar and indirect electron-mediated nuclear spin interactions, by the…
We studied the zero-field dynamic nuclear spin polarization in a single In$_{0.75}$Al$_{0.25}$As/Al$_{0.3}$Ga$_{0.7}$As quantum dot. Even without any external magnetic field, the positive trion excited by the circularly-polarized light…
We investigate in micro-photoluminescence experiments the dynamical nuclear polarization in individual InGaAs quantum dots. Experiments carried out in an applied magnetic field of 2T show that the nuclear polarization achieved through the…
We theoretically study the nuclear spin dynamics driven by electron transport and hyperfine interaction in an electrically-defined double quantum dot (DQD) in the Pauli-blockade regime. We derive a master-equation-based framework and show…
Coherent two-level systems, or qubits, based on electron spins in GaAs quantum dots are strongly coupled to the nuclear spins of the host lattice via the hyperfine interaction. Realizing nuclear spin control would likely improve electron…
Early experiments on spin-blockaded double quantum dots revealed surprising robust, large-amplitude current oscillations in the presence of a static (dc) source-drain bias [see e.g. K. Ono, S. Tarucha, Phys. Rev. Lett. 92, 256803 (2004)].…
We report the electrical induction and detection of dynamic nuclear polarization in the spin-blockade regime of double GaAs vertical quantum dots. The largest Overhauser field observed was about 4 Tesla, corresponding to a nuclear…
Spontaneous nuclear polarization is predicted in double quantum dots in the spin-blocked electron transport regime. The polarization results from an instability of the zero-polarization state when singlet and triplet electron energy levels…
We propose a scheme for the deterministic generation of steady-state entanglement between the two nuclear spin ensembles in an electrically defined double quantum dot. Due to quantum interference in the collective coupling to the electronic…
We consider the dynamic nuclear spin polarization (DNP) using two electrons in a double quantum dot in presence of external magnetic field and spin-orbit interaction, in various schemes of periodically repeated sweeps through the S-T+…