Electron spin resonance in two-dimensional electron gases

Summary form only given. While optical pump-probe techniques have proven quite successful in measuring the spin-dynamics and lifetimes of electrons in bulk samples, they cannot be easily applied to submicrometer structures and are limited to a large number of spins. New experimental techniques are needed to measure the spin dynamics of a small number of electrons in confined structures. Here, we discuss the design and initial experimental efforts using electrical detection of the electron spin resonance in AlGaAs and InGaAs based 2DEG transistors. We have fabricated high electron mobility transistors with integrated microwave lines in order to carry out electrical spin dynamics measurements. Using this novel approach we have broadband excitation capabilities and are applying the measurements to micrometer sized FET structures. The devices allow the electric field and microwave magnetic field excitations to be directly controlled, allowing the carrier concentration, the g-factor, and spin populations of the devices to be manipulated. The structures are easily modified to allow optical measurements of spin precession within the electron gas. These detection techniques should be capable of measuring a small number of spins (<10/sup /spl and//6) in a single, confined electron spin packet. The possibilities of using the technique to create spin-traps and measure the precessional dynamics of the trapped electrons in real time are also addressed.