title: Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface.
abstract: Spin-valves or spin-transistors in magnetic memories and logic elements are examples of structures whose functionality depends crucially on the length and time-scales at which spin-information is transferred through the device. In our work we employ spatially resolved optical pump-and-probe technique to investigate these fundamental spin-transport parameters in a model semiconductor system. We demonstrate that in an undoped GaAs/AlGaAs layer, spins are detected at distances reaching more than ten microns at times as short as nanoseconds. We have achieved this unprecedented combination of long-range and high-speed electronic spin-transport by simultaneously suppressing mechanisms that limit the spin life-time and the mobility of carriers. By exploring a series of structures we demonstrate that the GaAs/AlGaAs interface can provide superior spin-transport characteristics whether deposited directly on the substrate or embedded in complex semiconductor heterostructures. We confirm our conclusions by complementing the optical experiments with dc and terahertz photo-conductivity measurements.
authors.affiliation: Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.|Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic.
authors.forename: L
authors.initials: L
authors.lastname: Nádvorník
authors.affiliation: Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic.
authors.forename: P
authors.initials: P
authors.lastname: Němec
authors.affiliation: Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.|Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic.
authors.forename: T
authors.initials: T
authors.lastname: Janda
authors.affiliation: Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.
authors.forename: K
authors.initials: K
authors.lastname: Olejník
authors.affiliation: Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Novák
authors.affiliation: Institute of Physics ASCR, v.v.i., Na Slovance 2, 18221 Praha 8, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Skoromets
authors.affiliation: Institute of Physics ASCR, v.v.i., Na Slovance 2, 18221 Praha 8, Czech Republic.
authors.forename: H
authors.initials: H
authors.lastname: Němec
authors.affiliation: Institute of Physics ASCR, v.v.i., Na Slovance 2, 18221 Praha 8, Czech Republic.
authors.forename: P
authors.initials: P
authors.lastname: Kužel
authors.affiliation: Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic.
authors.forename: F
authors.initials: F
authors.lastname: Trojánek
authors.affiliation: Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.|School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: T
authors.initials: T
authors.lastname: Jungwirth
authors.affiliation: Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.|Hitachi Cambridge Laboratory, J. J. Thomson Avenue, CB3 0HE Cambridge, UK.
authors.forename: J
authors.initials: J
authors.lastname: Wunderlich