title: Critical exponents in metastable decay via quantum activation.
abstract: We consider decay of metastable states of forced vibrations of a quantum oscillator close to the bifurcation points where the states disappear. Decay occurs via quantum activation over a quasienergy barrier, a mechanism that differs from both tunneling and thermal activation. The decay probability W scales with the distance eta to the bifurcation point as /ln W/ proportional to eta(xi). The exponent xi is found for a resonantly driven oscillator and an oscillator modulated at nearly twice its eigenfrequency.
authors.affiliation: Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: M I
authors.initials: MI
authors.lastname: Dykman