Related papers: The coherence of quantum dot confined electron- an…
The spin fluctuations of electron and hole doped self-assembled quantum dot ensembles are measured optically in the low-intensity limit of a probe laser in absence and presence of longitudinal or transverse static magnetic fields. The…
The electron and hole states in a CdTe quantum dot containing a single magnetic impurity in an external magnetic field are investigated, using the multiband approximation which includes the heavy hole-light hole coupling effects. The…
The coherent spin dynamics of resident carriers, electrons and holes, in semiconductor quantum structures is studied by periodical optical excitation using short laser pulses and in an external magnetic field. The generation and dephasing…
The spin of an electron trapped in a quantum dot is a promising candidate implementation of a qubit for quantum information processing. We study the central spin problem of the effect of the hyperfine interaction between such an electron…
A heavy hole confined to an InGaAs quantum dot promises the union of a stable spin and optical coherence to form a near perfect, high-bandwidth spin-photon interface. Despite theoretical predictions and encouraging preliminary measurements,…
We investigate the coherent exciton spin dynamics in a single InAlAs/AlGaAs quantum dot using time-resolved quantum state tomography. Under two-LO-phonon quasi-resonant excitation of neutral exciton, we observe pronounced quantum beats in…
We study the decoherence of a spin in a quantum dot due to its hyperfine coupling to a randomly fluctuating bath of nuclear spins. The system is modelled by the central spin model with the spin bath initially being at infinite temperature.…
We study the long-time decay of fourth-order electron spin correlation functions for an isolated singly charged semi-conductor quantum dot. The electron spin dynamics is governed by the applied external magnetic field as well as the…
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…
The coherence of electron spin qubits in semiconductor quantum dots suffers mostly from low-frequency noise. During the last decade, efforts have been devoted to mitigate such noise by material engineering, leading to substantial…
In this article we review our work on the dynamics and decoherence of electron and hole spins in single and double quantum dots. The first part, on electron spins, focuses on decoherence induced via the hyperfine interaction while the…
For the realisation of scalable solid-state quantum-bit systems, spins in semiconductor quantum dots are promising candidates. A key requirement for quantum logic operations is a sufficiently long coherence time of the spin system.…
Recent time-resolved differential transmission and Faraday rotation measurements of long-lived electron spin coherence in quantum wells displayed intriguing parametric dependencies. For their understanding we formulate a microscopic theory…
We investigate quantum coherence of electron spin transported through a semiconductor spintronic device, where spins are envisaged to be controlled by electrical means via spin-orbit interactions. To quantify the degree of spin coherence,…
The spin of an electron in a semiconductor quantum dot represents a natural nanoscale solid state qubit. Coupling to nuclear spins leads to decoherence that limits the number of allowed quantum logic operations for this qubit. Traditional…
The main source of decoherence for an electron spin confined to a quantum dot is the hyperfine interaction with nuclear spins. To analyze this process theoretically we diagonalize the central spin Hamiltonian in the high magnetic B-field…
We theoretically investigate the spin dynamics of a heavy hole confined to an unstrained III-V semiconductor quantum dot and interacting with a narrowed nuclear-spin bath. We show that band hybridization leads to an exponential decay of…
In quantum dots made from materials with nonzero nuclear spins, hyperfine coupling creates a fluctuating effective Zeeman field (Overhauser field) felt by electrons, which can be a dominant source of spin qubit decoherence. We characterize…
We review recent studies on spin decoherence of electrons and holes in quasi-two-dimensional quantum dots, as well as electron-spin relaxation in nanowire quantum dots. The spins of confined electrons and holes are considered major…
We develop a theory for the spin-echo dynamics of a heavy hole in a quantum dot, accounting for both hyperfine- and electric-field-induced fluctuations. We show that a moderate applied magnetic field can drive this system to a…