title: Entangled electron and nuclear spin states in 15N@C60: density matrix tomography.
abstract: Procedures of the preparation and detection of entangled electron-nuclear spin states in (15)N@C(60) by combining electron spin resonance and electron nuclear double resonance pulse techniques are presented. A quantitative evaluation of the complete density matrix is obtained by a special density matrix tomography. All four Bell states of a two qubit subsystem were analyzed and experimental decoherence times are presented. In addition, we estimate a quantum critical temperature of T(q)=7.76 K for this system at an electron spin resonance frequency of 95 GHz.
authors.affiliation: 2. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Scherer
authors.forename: Michael
authors.initials: M
authors.lastname: Mehring