Temperature-dependent dynamical nuclear polarization bistabilities in double quantum dots in the spin-blockade regime

2012/11/30 by Anders Mathias Lunde, Carlos López-Monís, Ioanna A. Vasiliadou +3
Chemistry · Physics and Astronomy · #Atomic physics #Chemistry #Condensed matter physics #Electron #Excited state #Hyperfine structure #Magnetic field #Physics #Physics of Superconductivity and Magnetism #Polarization (electrochemistry) #Quantum and electron transport phenomena #Quantum dot #Quantum mechanics #Semiconductor Quantum Structures and Devices #Singlet state #Spin (aerodynamics) #Spin polarization #Spin-flip #cond-mat.mes-hall #nlin.CD

paper · pdf · doi:10.1103/physrevb.88.035317

published as Phys. Rev. B 88, 035317 (2013) · 26 pages, 17 figures

arxiv created 2013/07/29 · openalex publication_date 2013/07/29 · arxiv updated 2013/07/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The interplay of dynamical nuclear polarization (DNP) and leakage current through a double quantum dot in the spin-blockade regime is analyzed. A finite DNP is built up due to a competition between hyperfine (HF) spin-flip transitions and another inelastic escape mechanism from the triplets, which block transport. We focus on the temperature dependence of the DNP for zero energy detuning (i.e., equal electrostatic energy of one electron in each dot and a singlet in the right dot). Our main result is the existence of a transition temperature, below which the DNP is bistable, so a hysteretic leakage current versus external magnetic field B appears. This is studied in two cases: (i) close to the crossing of the three triplet energy levels near B=0, where spin-blockade is lifted due to the inhomogeneity of the effective magnetic field from the nuclei. (ii) At higher B-fields, where the two spin-polarized triplets simultaneously cross two different singlet energy levels. We develop simplified models leading to different transition temperatures T_c,TT and T_c,ST for the crossing of the triplet levels and the singlet-triplet level crossings, respectively. We find T_c,TT analytically to be given solely by the HF couplings, whereas T_c,ST depends on various parameters and T_c,ST>T_c,TT. The key idea behind the existence of the transition temperatures at zero energy detuning is the suppression of energy absorption compared to emission in the inelastic HF transitions. Finally, by comparing the rate equation results with Monte Carlo simulations, we discuss the importance of having both HF interaction and another escape mechanism from the triplets to induce a finite DNP.

Citations

• Hyperfine mediated triplet-singlet transition probability in a double-quantum-dot system: Analogy with the double-slit experiment
• Current-Induced Entanglement of Nuclear Spins in Quantum Dots
• Helical edge states coupled to a spin bath: Current-induced magnetization
• Dynamics of Quantum Dot Nuclear Spin Polarization Controlled by a Single Electron
• Self-Sustaining Dynamical Nuclear Polarization Oscillations in Quantum Dots
• Suppression of Spin Relaxation in an InAs Nanowire Double Quantum Dot
• Electronic structure of quantum dots
• Electrically Driven Reverse Overhauser Pumping of Nuclear Spins in Quantum Dots
• Singlet-triplet decoherence due to nuclear spins in a double quantum dot
• Electron-nuclei spin relaxation through phonon-assisted hyperfine interaction in a quantum dot
• Addition spectrum of a lateral dot from Coulomb and spin-blockade spectroscopy
• Two relaxation mechanisms observed in transport between spin-split edge states at high imbalance
• Spin-valley blockade in carbon nanotube double quantum dots
• Detection of spin injection into a double quantum dot: Violation of magnetic-field-inversion symmetry of nuclear polarization instabilities
• Theory of Phonon-Induced Spin Relaxation in Laterally Coupled Quantum Dots
• Hyperfine interaction and electron-spin decoherence in graphene and carbon nanotube quantum dots
• Dynamic nuclear polarization at the edge of a two-dimensional electron gas
• Hyperfine induced spin and entanglement dynamics in double quantum dots: A homogeneous coupling approach
• Pauli spin blockade in carbon nanotube double quantum dots
• Nucleus-mediated spin-flip transitions in GaAs quantum dots
• Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
• Spins in few-electron quantum dots
• Singlet-triplet splitting in double quantum dots due to spin-orbit and hyperfine interactions
• Control and Detection of Singlet-Triplet Mixing in a Random Nuclear Field
• Spin relaxation in semiconductor quantum dots