Related papers: Spin exchange interaction with tunable range betwe…
Because of their long coherence times and potential for scalability, semiconductor quantum-dot spin qubits hold great promise for quantum information processing. However, maintaining high connectivity between quantum-dot spin qubits, which…
We theoretically investigate quantum spin transfer from spin-correlated conduction-electron pairs to localized spins in a ferromagnet, given that electrons are correlated intrinsically. We show that even spin-singlet pairs and triplet pairs…
We give a concise account on the derivation of hybrid quantum-classical models for stationary electron transport in graphene, in presence of sharp potential steps of barriers. A quantum region (an asymptotically thin strip around the…
Using an ensemble of atoms in an optical cavity, we engineer a family of nonlocal Heisenberg Hamiltonians with continuously tunable anisotropy of the spin-spin couplings. We thus gain access to a rich phase diagram, including a…
We demonstrate how electric fields with arbitrary time profile can be used to control the time-dependent parameters of spin and orbital exchange Hamiltonians. Analytic expressions for the exchange constants are derived from a time-dependent…
Tunneling in a quantum coherent structure is not restricted to only nearest neighbours. Hopping between distant sites is possible via the virtual occupation of otherwise avoided intermediate states. Here we report the observation of long…
Removing a single-carbon vacancy introduces (quasi-)localized states for both and electrons in graphene. Interactions between the localized dangling bond and quasilocalized electrons of a single-carbon vacancy in graphene are predicted to…
We show within a local self-consistent mean-field treatment that a random distribution of magnetic adatoms can open a robust gap in the electronic spectrum of graphene. The electronic gap results from the interplay between the nature of the…
The low-lying eigenstates of a system of two electrons confined within a two-dimensional quantum dot with a hard polygonal boundary are obtained by means of exact diagonalization. The transition from a weakly correlated charge distribution…
Spintronics devices rely on spin-dependent transport behavior evoked by the presence of spin-polarized electrons. Transport through nanostructures, on the other hand, is dominated by strong Coulomb interaction. We study a model system in…
We investigate ground and excited state transport through small (d = 70 nm) graphene quantum dots. The successive spin filling of orbital states is detected by measuring the ground state energy as a function of a magnetic field. For a…
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 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 study indirect exchange interactions between localized spins of magnetic impurities in spin-valley coupled systems described with the Kane-Mele model. Our model captures the main ingredients of the energy bands of 1H transition metal…
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…
We review progress on the spintronics proposal for quantum computing where the quantum bits (qubits) are implemented with electron spins. We calculate the exchange interaction of coupled quantum dots and present experiments, where the…
Account of an intrinsic spin-orbit coupling in the valence bands of common semiconductors yields the scalar spin-orbit-rotation term in the effective-mass Hamiltonian of the conduction-band electron. This result is obtained within the…
Dispersively coupled distant qubits in a shared cavity can become entangled through virtual photon exchange with energy-conserving phase evolution of their quantum states. This interaction can potentially be accelerated by operating on…
The tunable band structure and nontrivial topology of multilayer rhombohedral graphene lead to a variety of correlated electronic states with isospin orders-meaning ordered states in the combined spin and valley degrees of freedom-dictated…
We present a microscopic theory for interacting graphene armchair nanoribbon quantum dots. Long range interaction processes are responsible for Coulomb blockade and spin-charge separation. Short range ones, arising from the underlying…