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Electron spin dynamics in GaN
Author(s) -
Rudolph Jörg,
Buß Jan Heye,
Hägele Daniel
Publication year - 2014
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201350185
Subject(s) - wurtzite crystal structure , condensed matter physics , spintronics , ferromagnetism , materials science , electron , spin polarization , relaxation (psychology) , spin (aerodynamics) , gallium nitride , physics , nanotechnology , zinc , psychology , social psychology , layer (electronics) , quantum mechanics , metallurgy , thermodynamics
Gallium nitride is a promising material system for spintronics, offering long spin relaxation times and prospects for room‐temperature ferromagnetism. We review the electron spin dynamics in bulk GaN. Time‐resolved magneto‐optical studies of both the wurtzite and the cubic phase of GaN show the dominance of Dyakonov–Perel (DP) relaxation for free conduction band electrons. Spin relaxation in the wurtzite phase is characterized by an intrinsic spin relaxation anisotropy and the limitation of spin lifetimes by a strong Rashba term. Spin lifetimes are strongly enhanced in cubic GaN, where only a weak Dresselhaus term contributes to DP relaxation. Ion‐implanted wurtzite GaN shows a strong increase of electron spin lifetimes for increasing implantation dose, caused by increasing localization of carriers. The spin dynamics of conduction band electrons in Gd‐implanted GaN as a candidate for a room‐temperature ferromagnetic semiconductor is also only governed by localization effects and does not show signs of an efficient exchange coupling between the electrons and the magnetic Gd ions.