相关论文: Intrinsic limit to electron spin coherence in InGa…

We demonstrate a coherence time of 2.1(1)~s for electron spin superposition states of a single trapped $^{40}$Ca$^+$ ion. The coherence time, measured with a spin-echo experiment, corresponds to residual rms magnetic field fluctuations…

The decoherence of a localized electron spin in a lattice of nuclear spins is an important problem for potential solid-state implementations of a quantum computer. We demonstrate that even at high fields, virtual electron spin-flip…

The nitrogen-vacancy (NV) centre, as a promising candidate solid state system of quantum information processing, its electron spin coherence is influenced by the magnetic field fluctuations due to the local environment. In pure diamonds,…

We review the progress and main challenges in implementing large-scale quantum computing by optical control of electron spins in quantum dots (QDs). Relevant systems include self-assembled QDs of III-V or II-VI compound semiconductors (such…

Interacting spin systems in solids underpin a wide range of quantum technologies, from quantum sensors and single-photon sources to spin-defect-based quantum registers and processors. We develop a quantum-computer-aided framework for…

Despite the importance of isotopically purified samples in current experiments, there have been few corresponding studies of spin qubit decoherence using full quantum bath calculations. Isotopic purification eliminates the well-studied…

Self-assembled quantum dots (QDs) are born out of lattice mismatched ingredients where strain plays an indispensable role. Through the electric quadrupolar coupling, strain affects the magnetic environment as seen by the nuclear spins. To…

The periodic optical orientation of electron spins in (In,Ga)As/GaAs quantum dots leads to the formation of electron spin precession modes about an external magnetic field which are resonant with the pumping periodicity. As the electron…

We estimate the spin relaxation rate due to spin-orbit coupling and acoustic phonon scattering in weakly-confined quantum dots with up to five interacting electrons. The Full Configuration Interaction approach is used to account for the…

We study the electron spin decoherence of encapsulated atomic hydrogen in octasilsesquioxane cages induced by the 1H and 29Si nuclear spin bath. By applying the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence we significantly suppress the…

The dynamics of a spin-1/2 particle coupled to a nuclear spin bath through an isotropic Heisenberg interaction is studied, as a model for the spin decoherence in quantum dots. The time-dependent polarization of the central spin is…

The spin dynamics of positively (X$^{+}$) and negatively (X$^{-}$) charged excitons in InP/In$_{0.48}$Ga$_{0.52}$P quantum dots subject to a magnetic field is studied. We find that a characteristic feature of the system under study is the…

We study theoretically the cooling of an ensemble of nuclear spins coupled to the spin of a localized electron in a quantum dot. We obtain a master equation for the state of the nuclear spins interacting with a sequence of polarized…

Single nuclear spins in the solid state have long been envisaged as a platform for quantum computing, due to their long coherence times and excellent controllability. Measurements can be performed via localised electrons, for example those…

We have measured the donor-bound electron spin dynamics in cubic GaN by time-resolved Kerr rotation experiments. The ensemble electron spin dephasing time in this quantum dot like system characterized by a Bohr radius of 2.5 nm is of the…

Several topics on the implementation of spin qubits in quantum dots are reviewed. We first provide an introduction to the standard model of quantum computing and the basic criteria for its realization. Other alternative formulations such as…

Matter qubits that maintain coherence over extended timescales are essential for many pursued applications in quantum communication and quantum computing. Significant progress has already been made on extending coherence times of spins in…

Carbon based systems are prominent candidates for a solid-state spin-qubit due to weak spin-orbit and hyperfine interactions in combination with a low natural abundance of spin carrying isotopes. We consider the effect of the hyperfine…

The coherence of electron spin can be significantly enhanced by locking the Overhauser field from nuclear spins using the nuclear spin preparation. We propose a theoretical model to calculate the long time dynamics of the Overhauser field…

A highly asymmetric dynamic nuclear spin pumping is observed in a single self assembled InGaAs quantum dot subject to resonant optical pumping of the neutral exciton transition leading to a large maximum polarization of 54%. This dynamic…