Suppression of electron spin decoherence in a quantum dot

Abstract

The dominant source of decoherence for an electron spin in a quantum dot is the hyperfine interaction with the surrounding bath of nuclear spins. The decoherence process may be slowed down by subjecting the electron spin to suitable sequences of external control pulses. We investigate the performance of a variety of dynamical decoupling protocols using exact numerical simulation. Emphasis is given to realistic pulse delays and the long-time limit, beyond the domain where available analytical approaches are guaranteed to work. Our results show that both deterministic and randomized protocols are capable to significantly prolong the electron coherence time, even when using control pulse separations substantially larger than what expected from the {\em upper cutoff} frequency of the coupling spectrum between the electron and the nuclear spins. In a realistic parameter range, the {\em total width} of such a coupling spectrum appears to be the physically relevant frequency scale affecting the overall quality of the decoupling.

8 pages, 3 figures. Invited talk at the XXXVII Winter Colloquium on the Physics of Quantum Electronics, Snowbird, Jan 2007. Submitted to J. Mod. Opt

References in corpus (12)

• Single-shot read-out of an individual electron spin in a quantum dot
• Driven coherent oscillations of a single electron spin in a quantum dot
• Fault-Tolerant Quantum Dynamical Decoupling
• Triplet-Singlet Spin Relaxation via Nuclei in a Double Quantum Dot
• Hyperfine interaction in a quantum dot: Non-Markovian electron spin dynamics
• Random decoupling schemes for quantum dynamical control and error suppression
• Restoring Coherence Lost to a Slow Interacting Mesoscopic Bath
• Quantum theory of spectral diffusion induced electron spin decoherence
• Numerical modeling of the central spin problem using the spin coherent states P-representation
• Quantum measurement of a mesoscopic spin ensemble
• Hyperfine interaction induced decoherence of electron spins in quantum dots
• Enhanced Convergence and Robust Performance of Randomized Dynamical Decoupling

Cited by in corpus (8)

• Dynamical Quantum Error Correction of Unitary Operations with Bounded Controls
• Long-time electron spin storage via dynamical suppression of hyperfine-induced decoherence in a quantum dot
• Coherent Control of Quantum Dynamics with Sequences of Unitary Phase-Kick Pulses
• Towards optimized suppression of dephasing in systems subject to pulse timing constraints
• Advantages of Randomization in Coherent Quantum Dynamical Control
• Uniaxial dynamical decoupling for an open quantum system
• Inhomogeneous dynamic nuclear polarization and suppression of electron-polarization decay in a quantum dot
• Quantum Zeno and anti-Zeno effects induced by either frequent measurements, modulations, or a mix of them