2007/12/31 by Wayne Witzel, W. M. Witzel, S. Das Sarma · 1 citation
Chemistry · Physics and Astronomy · #Advanced NMR Techniques and Applications #Coherence (philosophical gambling strategy) #Condensed matter physics #Dephasing #Dynamical decoupling #Electron #Physics #Quantum #Quantum and electron transport phenomena #Quantum decoherence #Quantum electrodynamics #Quantum mechanics #Quantum optics and atomic interactions #Qubit #Singlet state #Spin (aerodynamics) #Spin engineering #Spin polarization #Spins #Wave function #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.77.165319
published as Phys. Rev. B 77, 165319 (2008)
arxiv created 2008/04/11 · openalex publication_date 2008/04/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Decoherence of a localized electron spin in a solid state material (the ``central spin'' problem) at low temperature is believed to be dominated by interactions with nuclear spins in the lattice. This decoherence is partially suppressed through the application of a large magnetic field that splits the energy levels of the electron spin and prevents depolarization. However, the dephasing decoherence resulting from a dynamical nuclear spin bath cannot be removed in this way. Fluctuations of the nuclear field lead to an uncertainty of the electron's precessional frequency in a process known as spectral diffusion. This paper considers the effect of the electron's wavefunction shape on spectral diffusion and provides wavefunction dependent decoherence time formulas for a free induction decay as well as spin echoes and concatenated dynamical decoupling schemes for enhancing coherence. We also discuss a dephasing of a qubit encoded in singlet-triplet states of a double quantum dot. A central theoretical result of this work is the development of a continuum approximation for the spectral diffusion problem which we have applied to GaAs and InAs materials specifically.