Quantum Computing

Quantum Computing
Bell state of two entangled qubits

Magnetic Resonance is among the most promising technologies for Quantum Computing investigations. Both pulsed EPR and NMR (and combination techniques like pulsed ENDOR) provide comprehensive means to selectively and coherently manipulate individual transitions necessary, for examples, to create pure and entangled quantum states.
 
Qubit or quantum bit is a unit of quantum information. The striking difference compared to bits is quantum entanglement. This directly leads to quantum parallelism, i.e., the potential of quantum computers to solve problems must faster than regular systems. Another consequence of entanglement is non-locality, leading to the famous EPR paradox “Gedankenexperiment”. As noted in passing, the EPR abbreviation stands for both, Einstein-Podolsky-Rosen as well as Electron Paramagnetic Resonance.
 
Very recently, J. Morton and co-workers (Solid-State quantum memory using 31P nuclear spin, Nature 455 (2008) 1085) have demonstrated a sizeable quantum memory effect of 31P in 28Si crystal. A high fidelity was obtained at 5.5 K. Pulsed ENDOR was applied to transfer the qubit information coherently using Bruker’s ELEXSYS E580 Pulsed EPR spectrometer.