Related papers: Spin interactions and switching in vertically tunn…
We investigate the spin of the ground state of a geometrically confined many-electron system. For atoms, shell structure simplifies this problem-- the spin is prescribed by the well-known Hund's rule. In contrast, quantum dots provide a…
We optically probe and electrically control a single artificial molecule containing a well defined number of electrons. Charge and spin dependent inter-dot quantum couplings are probed optically by adding a single electron-hole pair and…
Theoretical analysis of the experimental data for the energy levels of two interacting electrons confined by a finite Gaussian potential in a 2D quantum dot and subjected to a uniform magnetic field perpendicular to the plane of the dot is…
We determine the contributions from the direct Coulomb and exchange interactions to the total interaction in semiconductor artificial atoms. We tune the relative strengths of the two interactions and measure them as a function of the number…
Spin-dependent electronic transport through a quantum dot has been analyzed theoretically in the cotunneling regime by means of the second-order perturbation theory. The system is described by the impurity Anderson Hamiltonian with…
Recent experiments on semiconductor quantum dots have demonstrated the ability to utilize a large quantum dot to mediate superexchange interactions and generate entanglement between distant spins. This opens up a possible mechanism for…
We consider a quantum dot embedded in a three-dimensional nanowire with tunable aspect ratio a. A configuration interaction theory is developed to calculate the energy spectra of the finite 1D quantum dot systems charged with two electrons…
We present a theory for understanding the exchange interaction between electron spins in neighboring quantum dots, either by changing the detuning of the two quantum dots or independently tuning the tunneling barrier between quantum dots.…
We present a general formulation of spin-dependent transport through a clean one-dimensional interacting quantum wire or carbon nanotube, connected to non-collinear ferromagnets via tunnel junctions. We show that the low energy description…
We measure singlet-triplet dephasing in a two-electron double quantum dot in the presence of an exchange interaction which can be electrically tuned from much smaller to much larger than the hyperfine energy. Saturation of dephasing and…
We investigate theoretically the combined effects of the electron-electron and the Rashba spin-orbit interactions on two electrons confined in quasi-one-dimensional AlInSb-based double quantum dots. We calculate the two-electron wave…
Few-electron states in carbon-nanotube quantum dots are studied by means of the configuration-interaction method. The peculiar non-interacting feature of the tunneling spectrum for two electrons, recently measured by Kuemmeth et al. [Nature…
The spin-orbit coupling influences the total spin of semiconductor quantum dots. We analyze the theoretical prediction for the combined effects of spin-orbit coupling, weak vertical magnetic fields and deformation of the dot. Our results…
The spin-orbit interaction is the key element for electrically tunable spin qubits. Here we probe the effect of cubic Rashba spin-orbit interaction on mixing of the spin states by investigating singlet-triplet oscillations in a planar Ge…
We report the observation of an unusually large number of consecutive spin pairs in a weakly coupled many-electron GaAs/AlGaAs quantum dot. The pairs are identified due to pairwise parallel shifts of Coulomb resonances in a perpendicular…
Semiconductor quantum dots (QDs) offer a platform to explore the physics of quantum electronics including spins. Electron spins in QDs are considered good candidates for quantum bits in quantum information processing, and spin control and…
We present a theoretical study of the spectrum of electrons confined in triple concentric rings. An unusual ordering and rich variety of angular momentum transitions are found that depend on the coupling between the rings and the…
Calculations for two electrons in an elliptic quantum dot, using symmetry breaking at the unrestricted Hartree-Fock level and subsequent restoration of the broken parity via projection techniques, show that the electrons can localize and…
A single electron shared between two levels threaded by a magnetic flux is an irreducibly simple quantum system in which interference is predicted to occur. We demonstrate tuning of the tunnel coupling between two such electronic levels…
Manipulation of spin states at the single-atom scale underlies spin-based quantum information processing and spintronic devices. Such applications require protection of the spin states against quantum decoherence due to interactions with…