title: Coherent Spin Dynamics in Molecular Cr8Zn Wheels.
abstract: Controlling and understanding transitions between molecular spin states allows selection of the most suitable ones for qubit encoding. Here we present a detailed investigation of single crystals of a polynuclear Cr8Zn molecular wheel using 241 GHz electron paramagnetic resonance (EPR) spectroscopy in high magnetic field. Continuous wave spectra are well reproduced by spin Hamiltonian calculations, which evidence that transitions in correspondence to a well-defined anticrossing involve mixed states with different total spin. We studied, by means of spin echo experiments, the temperature dependence of the dephasing time (T2) down to 1.35 K. These results are reproduced by considering both hyperfine and intermolecular dipolar interactions, evidencing that the dipolar contribution is completely suppressed at the lowest temperature. Overall, these results shed light on the effects of the decoherence mechanisms, whose understanding is crucial to exploit chemically engineered molecular states as a resource for quantum information processing.
authors.affiliation: Istituto Nanoscienze-CNR , via G. Campi 213A, 41125 Modena, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ghirri
authors.affiliation: Dipartimento di Fisica e Scienze della Terra, Università di Parma , Parco Area delle Scienze 7/a, 43123 Parma, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Chiesa
authors.affiliation: Dipartimento di Fisica e Scienze della Terra, Università di Parma , Parco Area delle Scienze 7/a, 43123 Parma, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Carretta
authors.affiliation: Istituto Nanoscienze-CNR , via G. Campi 213A, 41125 Modena, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Troiani
authors.affiliation: National High Magnetic Field Laboratory , Tallahassee, Florida 32310, United States.
authors.forename: Johan
authors.initials: J
authors.lastname: van Tol
authors.affiliation: National High Magnetic Field Laboratory , Tallahassee, Florida 32310, United States.|Department of Physics, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Stephen
authors.initials: S
authors.lastname: Hill
authors.affiliation: School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Inigo
authors.initials: I
authors.lastname: Vitorica-Yrezabal
authors.affiliation: School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Grigore A
authors.initials: GA
authors.lastname: Timco
authors.affiliation: School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Richard E P
authors.initials: RE
authors.lastname: Winpenny
authors.affiliation: Istituto Nanoscienze-CNR , via G. Campi 213A, 41125 Modena, Italy.|Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia , via Campi 213A, 41125 Modena, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Affronte
keywords: decoherence; electron paramagnetic resonance; molecular spin states