Ultrafast Probes of Nonequilibrium Hole Spin Relaxation in Ferromagnetic Semiconductor GaMnAs

Abstract

We directly measure the hole spin lifetime in ferromagnetic GaMnAs via time- and polarization-resolved spectroscopy. Below the Curie temperature Tc, an ultrafast photoexcitation with linearly-polarized light is shown to create a non-equilibrium hole spin population via the dynamical polarization of holes through p-d exchange scattering with ferromagnetically-ordered Mn spins, and we characterize their relaxation dynamics. The observed relaxation consists of a distinct three-step recovery : (i) femtosecond (fs) hole spin relaxation ~ $160-200 fs, (ii) picosecond (ps) hole energy relaxation ~ 1-2 ps, and (iii) a coherent, damped Mn spin precession with a period of ~ 250 ps. The transient amplitude of the hole spin component diminishes with increasing temperature, directly following the ferromagnetic order, while the hole energy amplitude shows negligible temperature change, consistent with our interpretation. Our results thus establish the hole spin lifetimes in ferromagnetic semiconductors and demonstrate a novel spectroscopy method for studying non-equilibrium hole spins in the presence of correlation and magnetic order.

References in corpus (21)

• Coherent magnetization precession in ferromagnetic (Ga,Mn)As induced by picosecond acoustic pulses
• Controlling Curie temperature in (Ga,Ms)As through location of the Fermi level within the impurity band
• Photo-induced precession of magnetization in ferromagnetic (Ga,Mn)As
• Ultrafast Quenching of Ferromagnetism in InMnAs Induced by Intense Laser Irradiation
• Ultrafast Enhancement of Ferromagnetism via Photoexcited Holes in GaMnAs
• Ultrafast demagnetization in the sp-d model: a theoretical study
• Ultrafast observation of critical nematic fluctuations and giant magnetoelastic coupling in iron pnictides
• Experimental observation of the optical spin-orbit torque
• Observation of the spin-charge thermal isolation of ferromagnetic Ga_{0.94}Mn_{0.06}As by time-resolved magneto-optical measurement
• Light-induced magnetization precession in GaMnAs
• Coherent Magnetization Precession in GaMnAs induced by Ultrafast Optical Excitation
• Femtosecond Demagnetization and Hot Hole Relaxation in Ferromagnetic GaMnAs
• Femtosecond Coherent Control of Spin with Light in (Ga,Mn)As ferromagnets
• Temperature and magnetization-dependent band-gap renormalization and optical many-body effects in diluted magnetic semiconductors
• Propagating Coherent Acoustic Phonon Wavepackets in InMnAs/GaSb
• Coherent control of magnetization precession in ferromagnetic semiconductor (Ga,Mn)As
• Spin Accumulation in Nondegenerate and Heavily Doped p-Type Germanium
• Bipolar spintronics: From spin injection to spin-controlled logic
• Theory of carrier dynamics and time resolved reflectivity in InMnAs/GaSb heterostructures
• All-optical four-state magnetization reversal in (Ga,Mn)As ferromagnetic semiconductors
• Hole spin relaxation and coefficients in Landau-Lifshitz-Gilbert equation in ferromagnetic GaMnAs

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