Spin decoherence in graphene quantum dots due to hyperfine interaction
arXiv:1204.5112 · doi:10.1103/PhysRevB.86.085301
Abstract
Carbon based systems are prominent candidates for a solid-state spin-qubit due to weak spin-orbit and hyperfine interactions in combination with a low natural abundance of spin carrying isotopes. We consider the effect of the hyperfine interaction on the coherence of an electron-spin localized in a graphene quantum dot. It is known, that the hyperfine interaction in these systems is anisotropic promising interesting physics. We calculate the dynamics of an electron spin surrounded by a bath of nuclear spins in a non-Markovian approach using a generalized master equation. Considering a general form of the hyperfine interaction, we are able to extend the range of validity of our results to other systems beyond graphene. For large external magnetic fields, we find within Born approximation that the electron spin state is conserved up to small corrections, which oscillate with a frequency determined by the hyperfine interaction. The amplitude of these oscillations decays with a power law, where its initial value depends on the specific form of the anisotropy. Analyzing this in more detail, we identify two distinct classes of anisotropy, which can be both found in graphene depending on the orientation of the external magnetic field with respect to the carbon layer.
19 pages, 7 figures
References in corpus (28)
- Chaotic Dirac billiard in graphene quantum dots
- Biased bilayer graphene: semiconductor with a gap tunable by electric field effect
- Spin qubits in graphene quantum dots
- Magnetic confinement of massless Dirac fermions in graphene
- Hyperfine interaction in a quantum dot: Non-Markovian electron spin dynamics
- Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
- Quantum dots in graphene
- Theory of electron spin decoherence by interacting nuclear spins in a quantum dot
- Spin decoherence of a heavy hole coupled to nuclear spins in a quantum dot
- Tunable Coulomb blockade in nanostructured graphene
- Enhancing the Coherence of a Spin Qubit by Operating it as a Feedback Loop That Controls its Nuclear Spin Bath
- Electron Spin Dephasing due to Hyperfine Interactions with a Nuclear Spin Bath
- Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots
- Quasi-bound states of quantum dots in single and bilayer graphene
- Recipes for spin-based quantum computing
- Observation of excited states in a graphene quantum dot
- Hole - Nuclear Spin Interaction in Quantum Dots
- Nuclear Spins in Nanostructures
- Hyperfine interaction and electron-spin decoherence in graphene and carbon nanotube quantum dots
- Hyperfine Interactions in Graphene and Related Carbon Nanostructures
- Dynamic nuclear polarization and spin-diffusion in non-conducting solids
- Exponential decay in a spin bath
- Hybridization and spin decoherence in heavy-hole quantum dots
- Decoherence induced by anisotropic hyperfine interaction in Si spin qubits
- Time-resolved charge detection in graphene quantum dots
- Nuclear spin dynamics and Zeno effect in quantum dots and defect centers
- Non-ideality of quantum operations with the electron spin of a 31P donor in a Si crystal due to interaction with a nuclear spin system
- Gate-tunable split Kondo effect in a carbon nanotube quantum dot