| Abstract: |
Quantum computers will use quantum mechanical properties to perform certain tasks much faster than traditional computers. Realization of one quantum computing scheme requires a measurement of the T2 electron spin lifetime in GaAs. Electron and nuclear interactions prevent an accurate measurement of T2 by optically detected spin echo. Attempts to eliminate nuclear effects using NMR have been unsuccessful, probably due to insufficient magnetic field strength at one or more of the three resonant frequencies. Transmission line effects and mismatched impedances may have limited the current delivered to the NMR coil. Several impedance matching methods are considered, using computer models to account for transmission line effects and predict current delivered to the coil. Two methods are selected—both use three coils on the same circuit, each tuned to one of the resonant frequencies. Experiments show that neither method is a viable solution. It is recommended that further tests be performed with three coils on separate circuits, each tuned and driven around one of the resonant frequencies. |