Related papers: Singlet-triplet transition in double quantum dots …

We investigate quantum phase transitions (QPTs) in spin chain systems characterized by local Hamiltonians with matrix product ground states. We show how to theoretically engineer such QPT points between states with predetermined properties.…

We investigate the Kondo effect in the two-dimensional electron system with a non-trivial quadratic energy band crossing point. We show that the Kondo effect can induce a new hybrid topological insulator phase which is a coexistence state…

We investigate the use of external time-dependent magnetic field for the control of the quantum states in a two-electron quantum ring. The hyperfine interaction of the confined electrons with surrounding nuclei couples the singlet state…

We study ground states and far-infrared spectra (FIR) of two electrons in four-minima quantum-dot molecule in magnetic field by exact diagonalization. Ground states consist of altering singlet and triplet states, whose frequency, as a…

Based on symmetry constraint that leads to the appearance of nodes in the wave functions of 3-electron systems at regular triangle configurations, it was found that, if the parameters of confinement are skillfully given and if a magnetic…

We report sharp peaks in the differential conductance of a single-electron transistor (SET) at low temperature, for gate voltages at which charge fluctuations are suppressed. For odd numbers of electrons we observe the expected Kondo peak…

We review here some universal aspects of the physics of two-electron molecular transistors in the absence of strong spin-orbit effects. Several recent quantum dots experiments have shown that an electrostatic backgate could be used to…

Recently, the electron transport through a quasi-one dimensional (quasi-1D) electron gas was investigated experimentally as a function of the confining potential. We present a physical model for quantum ballistic transport of electrons…

We apply an elementary measurement scheme to calculate the electronic triplet-singlet transition mediated by hyperfine interaction in a double quantum dot. We show how the local character of the hyperfine interaction and the nuclear…

We propose a cold-atom setup which allows for a dimensional crossover from a two-dimensional quantum spin Hall insulating phase to a three-dimensional strong topological insulator by tuning the hopping between the layers. We further show…

We propose a simple setup of three coupled quantum dots in the Coulomb blockade regime as a source for spatially separated currents of spin-entangled electrons. The entanglement originates from the singlet ground state of a quantum dot with…

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…

We study coupled semiconductor quantum dots theoretically through a generalized Hubbard approach, where intra- and inter-dot Coulomb Correlation, as well as tunneling effects are described on the basis of realistic electron wavefunctions.…

Quantum phase transitions are sudden changes in the ground-state wavefunction of a many-body system that can occur as a control parameter such as a concentration or a field strength is varied. They are driven purely by the competition…

It has been experimentally shown that negative exchange interactions can arise in a linear three-dot system when a two-electron double quantum dot is exchange coupled to a larger quantum dot containing on the order of one hundred electrons.…

We observe mixing between two-electron singlet and triplet states in a double quantum dot, caused by interactions with nuclear spins in the host semiconductor. This mixing is suppressed by applying a small magnetic field, or by increasing…

We consider a three-port single-level quantum dot system with one input and two output leads. Instead of considering an empty dot, we study the situations that two input electrons co-tunnel through the quantum dot occupied by one or two dot…

Coupled pairs of nuclear spins-1/2 support one singlet state and three triplet states. Transitions between the singlet state and one of the triplet states may be driven by an oscillating low-frequency magnetic field, in the presence of…

We study the coupling between a singlet-triplet qubit realized in a double quantum dot to a topological qubit realized by spatially well-separated Majorana bound states. We demonstrate that the singlet-triplet qubit can be leveraged for…

Singlet-triplet spin blockade in a few-electron lateral double quantum dot is investigated using simultaneous transport and charge-sensing measurements. Transport from the (1,1) to the (0,2) electron occupancy states is strongly suppressed…