Spectrum of an electron spin coupled to an unpolarized bath of nuclear spins

Abstract

The main source of decoherence for an electron spin confined to a quantum dot is the hyperfine interaction with nuclear spins. To analyze this process theoretically we diagonalize the central spin Hamiltonian in the high magnetic B-field limit. Then we project the eigenstates onto an unpolarized state of the nuclear bath and find that the resulting density of states has Gaussian tails. The level spacing of the nuclear sublevels is exponentially small in the middle of each of the two electron Zeeman levels but increases super-exponentially away from the center. This suggests to select states from the wings of the distribution when the system is projected on a single eigenstate by a measurement to reduce the noise of the nuclear spin bath. This theory is valid when the external magnetic field is larger than a typical Overhauser field at high nuclear spin temperature.

9 pages, 3 figures

References in corpus (3)

• Hyperfine interaction in a quantum dot: Non-Markovian electron spin dynamics
• Enhancing the Coherence of a Spin Qubit by Operating it as a Feedback Loop That Controls its Nuclear Spin Bath
• Magnetic Ordering of Nuclear Spins in an Interacting 2D Electron Gas

Cited by in corpus (9)

• Integrability-based analysis of the hyperfine-interaction -nduced decoherence in quantum dots
• Role of Nuclear Quadrupole Coupling on Decoherence and Relaxation of Central Spins in Quantum Dots
• Electrical spin orientation, spin-galvanic and spin-Hall effects in disordered two-dimensional systems
• Preparation of Non-equilibrium Nuclear Spin States in Double Quantum Dots
• Quantum limit for nuclear spin polarization in semiconductor quantum dots
• The importance of level statistics for the decoherence of a central spin due to a spin environment
• Spin textures in strongly coupled electron spin and magnetic or nuclear spin systems in quantum dots
• Wavelet-resolved coherence beats in the Overhauser field of a thermal nuclear spin ensemble
• Dipolar broadening of nuclear spin resonance under dynamical pumping