A combined experimental setup for OP and ODNMR

Detección del flip-flop de los centros paramagnéticos del GaAsN mediante bombeo óptico en régimen pulsado

“…Las técnicas basadas en resonancia magnética nuclear proporcionan los medios para controlar los estados nucleares [8] y sondear los principales mecanismos de polarización nuclear [25][26][27][28][29][30]. Sin embargo, estas técnicas tienen una muy baja sensibilidad de detección causada principalmente por la débil magnetización de los espines nucleares [31].…”

“…wherex andp are the position and momentum operators following the standard commutation relations. Aside from the simple harmonic oscillator, a large number of interesting systems arise from this Hamiltonian as the linear potential, 28,29 the driven harmonic oscillator, 30,31 Kanai-Caldirola Hamiltonians, [16][17][18][19][20][21] and time dependent harmonic oscillators, i.e., an oscillator with time-varying frequency. 21,32,33 The time evolution generated by the most general version of (1) has been studied by means of Lewis and Riesenfeld 34 invariants 35 and through linear invariants.…”

“…Some special cases emerging from these Hamiltonians have been studied by diverse mathematical methods. For instance, the time dependent linear potential has been treated through the Lewis and Riesenfeld 34 invariant theory, 28,29,36 Feynman's path integrals, [37][38][39][40][41] Similar to nitrogen-vacancy centers in diamond and impurity atoms in silicon, interstitial gallium deep paramagnetic centers in GaAsN have been proven to have useful characteristics for the development of spintronic devices. Among other interesting properties, under circularly polarized light, gallium centers act as spin filters that dynamically polarize free and bound electrons reaching record spin polarizations (close to 100%).…”

“…One of them is the spin-dependent recombination (SDR) [20][21][22][23][24][25][26][27]. In Ga(In)NAs alloys, Ga 2+ i paramagnetic centers with only one bound electron can selectively capture another conduction band (CB) electron with the opposite spin orientation [26][27][28][29][30]. Due to this mechanism, paramagnetic centers act as a spin filter that blocks the recombination of CB electrons with the same spin and efficiently captures electrons whose spin is in the opposite direction.…”

“…Optically or electrically detected magnetic resonance techniques are consistently employed for manipulating and probing defect spins through the hyperfine interaction and also to identify the defect chemical nature [26,27]. Optically detected magnetic resonance, a variation of nuclear resonance techniques, has been demonstrated on Cr 4+ impurity ensembles in SiC and GaN [28]. Mostly due to the weak magnetization of nuclear spins, these methods have very low sensitivity.…”