Electrical current and coupled electron-nuclear spin dynamics in double quantum dots

  title={Electrical current and coupled electron-nuclear spin dynamics in double quantum dots},
  author={G. Giavaras and Neill Lambert and Franco Nori},
  journal={Physical Review B},
We examine electronic transport in a spin-blockaded double quantum dot. We show that by tuning the strength of the spin-orbit interaction the current flowing through the double dot exhibits a dip at zero magnetic field or a peak at a magnetic field for which the two-electron energy levels anticross. This behaviour is due to the dependence of the singlet-triplet mixing on the field and spin-orbit amplitude. We derive approximate expressions for the current as a function of the amplitudes of the… 

Figures from this paper

Spin–orbit interaction induced current dip in a single quantum dot coupled to a spin
Abstract Experiments on semiconductor quantum dot systems have demonstrated the coupling between electron spins in quantum dots and spins localized in the neighboring area of the dots. Here we show
Transport spectroscopy of a spin-orbit-coupled spin to a quantum dot
Electron spins in quantum dots can interact with impurity spins located in an adjacent region. This interaction may be controllable using external electric fields and it can involve an appreciable
Nuclear spin dynamics in double quantum dots: Multistability, dynamical polarization, criticality, and entanglement
We theoretically study the nuclear spin dynamics driven by electron transport and hyperfine interaction in an electrically defined double quantum dot in the Pauli-blockade regime. We derive a
Probing the singlet-triplet splitting in double quantum dots: Implications of the ac field amplitude
We consider a double quantum dot whose energy detuning is controlled by an ac electric field. We demonstrate an energy configuration for which the ac-induced current flowing through the double dot
Microwave spectroscopy of spin–orbit coupled states: Energy detuning vs interdot coupling modulation
We study the AC field induced current peaks of a spin-blockaded double quantum dot with spin–orbit interaction. The AC field modulates either the interdot tunnel coupling or the energy detuning, and
Spectroscopy of double quantum dot two-spin states by tuning the interdot barrier
Transport spectroscopy of two-spin states in a double quantum dot can be performed by an AC electric field which tunes the energy detuning. However, a problem arises when the transition rate between
Transport through a quantum dot spin-orbit coupled to an impurity site
The presence of impurity sites in the neighboring area of quantum dot systems has been inferred in various experiments. The impurity sites can be strongly coupled to the dots inducing additional
Quantum Dots for Quantum Information Processing: Controlling and Exploiting the Quantum Dot Environment
Electron spins confined in quantum dots (QDs) are among the leading contenders for implementing quantum information processing. In this thesis, we address two of the most significant technological
Properties of Heat Generation in a Double Quantum Dot
We investigate the electronic-current-induced heat generation in a double quantum dot connected by two normal leads. The dots are coupled in series with a coupling strength td. It is found that, at
Quantum thermodynamic devices: from theoretical proposals to experimental reality
reality Nathan M. Myers, 2, a) Obinna Abah, b) and Sebastian Deffner 4, c) Department of Physics, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA Computer, Computational and


Electron spin relaxation by nuclei in semiconductor quantum dots
We have studied theoretically electron spin relaxation in semiconductor quantum dots via interaction with nuclear spins. The relaxation is shown to be determined by three processes: (i) the
Nuclear-spin-induced oscillatory current in spin-blockaded quantum dots.
We show experimentally that electron transport through GaAs-based double quantum dots can be affected by ambient nuclear spin states in a certain regime where transport is blocked in the absence of
Dynamical Magnetic and Nuclear Polarization in Complex Spin Systems: Semi-magnetic II-VI Quantum Dots
Dynamical magnetic and nuclear polarization in complex spin systems is discussed on the example of transfer of spin from exciton to the central spin of magnetic impurity in a quantum dot in the
Phase transitions in dissipative quantum transport and mesoscopic nuclear spin pumping
Topological phase transitions can occur in the dissipative dynamics of a quantum system when the ratio of matrix elements for competing transport channels is varied. Here we establish a relation
Nuclear spin dynamics in double quantum dots: Fixed points, transients, and intermittency
Transport through spin-blockaded quantum dots provides a means for electrical control and detection of nuclear spin dynamics in the host material. Although such experiments have become increasingly
Dynamics of Electrons and Nuclei in Double Quantum Dots in the Spin Blockade Regime
Electron-nuclear interaction is a classic subject of condensed matter physics, studied extensively over decades by using nuclear magnetic resonance. This seemingly mature field has been attracting
Dynamic nuclear polarization with single electron spins.
A self-limiting pulse sequence is developed that allows the steady-state nuclear polarization to be set using a gate voltage and the resulting Overhauser field approaches 80 mT, in agreement with a simple rate-equation model.
Observation of hysteretic transport due to dynamic nuclear spin polarization in a GaAs lateral double quantum dot.
A new transport feature in a GaAs lateral double quantum dot that emerges for magnetic-field sweeps and shows hysteresis due to dynamic nuclear spin polarization (DNP) opens up the possibility of controlling electron and nuclear spin states via dc transport.
Pauli spin blockade in the presence of strong spin-orbit coupling
We study electron transport in a double quantum dot in the Pauli spin blockade regime in the presence of strong spin-orbit coupling. The effect of spin-orbit coupling is incorporated into a modified
Voltage-selective bidirectional polarization and coherent rotation of nuclear spins in quantum dots.
This Letter confirms that the nuclear spins in quantum dots are long-lived quantum states with a coherence time of up to 1 ms, and may be a promising resource for quantum-information processing such as quantum memories for electron spin qubits.