Related papers: Electrical manipulation of an electronic two-state…
Ground state of two-electron quantum dots in single-valley materials like GaAs is always a spin singlet regardless of what the potential and interactions are. This statement cannot be generalized to the multi-valley materials like $n$-doped…
We study exchange coupling in Si double quantum dots, which have been proposed as suitable candidates for spin qubits due to their long spin coherence times. We discuss in detail two alternative schemes which have been proposed for…
Electronic states in silicon quantum dots are examined theoretically, taking into account a multivalley structure of the conduction band. We find that (i) exchange interaction hardly works between electrons in different valleys. In…
We measure the excited-state spectrum of a Si/SiGe quantum dot as a function of in-plane magnetic field, and we identify the spin of the lowest three eigenstates in an effective two-electron regime. The singlet-triplet splitting is an…
Manipulation of the spin-states of a quantum dot by purely electrical means is a highly desirable property of fundamental importance for the development of spintronic devices such as spin-filters, spin-transistors and single-spin memory as…
We design and analyze a solid state qubit based on electron spin and controlled by electrical means. The coded qubit is composed of a three-electron complex in three tunable gated quantum dots. The two logical states of a qubit, |0L> and…
Recent experiments have demonstrated quantum manipulation of two-electron spin states in double quantum dots using electrically controlled exchange interactions. Here, we present a detailed theory for electron spin dynamics in two-electron…
A double-quantum-dot coupled to electrodes with spin-dependent splitting of chemical potentials (spin bias) is investigated theoretically by means of the Green's functions formalism. By applying a large spin bias, the quantum spin in a…
We study theoretically the electron states in a system of two vertically stacked quantum dots. We investigate the influence of the geometrical symmetry breaking (caused by the displacement as well as the ellipticity of the dots) on the…
We propose an approach to reconstruct two-electron spin qubit states in semiconductor quantum dots by employing tomographic techniques. This procedure exploits the combination of fast gate operations on electron spins trapped in dots and…
We demonstrate high-fidelity reversible transfer of quantum information from the polarisation of photons into the spin-state of an electron-hole pair in a semiconductor quantum dot. Moreover, spins are electrically manipulated on a…
Kondo conduction has been observed in a quantum dot with an even number of electrons at the Triplet-Singlet degeneracy point produced by applying a small magnetic field $B$ orthogonal to the dot plane. At a much larger field $ B \sim B_*$,…
Achieving control over the electron spin in quantum dots (artificial atoms) or real atoms promises access to new technologies in conventional and in quantum information processing. Here we review our proposal for quantum computing with…
We show that spin-orbit coupling in a quantum dot molecule allows for coherent manipulation of two electron spin states using Raman transitions. Such two-electron spin states defined by the singlet and triplet states of two exchange coupled…
Some of the most intriguing problems in solid state physics arise when the motion of one electron dramatically affects the motion of surrounding electrons. Traditionally, such highly-correlated electron systems have been studied mainly in…
We present an analytically solvable model of $P$ colinear, two-dimensional quantum dots, each containing two electrons. Inter-dot coupling via the electron-electron interaction gives rise to sets of entangled ground states. These ground…
The signature of coherent coupling between two quantum states is an anticrossing in their energies as one is swept through the other. In single semiconductor quantum dots containing an electron-hole pair the eigenstates form a two-level…
We investigated electron transport through ultra small Si quantum dots. We found that the $B$-dependence of energy levels is dominated by the Zeeman shift, allowing us to measure the spin difference between two successive ground states…
We simulate the control of the spin states in a two-electron double quantum dot when an external detuning potential is used for passing the system through an anticrossing. The hyperfine coupling of the electron spins with the surrounding…
The possibility of a novel type of semiconductor quantum dots obtained by spatially modulating the spin-orbit coupling intensity in III-V heterostructures is discussed. Using the effective mass model we predict confined one-electron states…