Journal of the Physical Society of Japan
Frequency-Locking Phenomenon of Two Weakly Coupled Bose–Einstein Condensates Induced by Periodic Bias Modulation
Noriaki Tsukada, Kensuke Fukushima, Takashi Suzuki
Abstract
We investigate the effect of periodic bias modulation on two weakly coupled Bose–Einstein condensates in a symmetric double-well potential and find a frequency-locking phenomenon at the transition frequency between the symmetric and antisymmetric states. Frequency-locking phenomenon becomes noticeable when the amplitude of the bias modulation is increased. The transition frequency becomes constant over a certain region of positive and negative nonlinear parameters due to the population mixing between the two states induced by the bias modulation. The frequency-locking phenomenon is also found in the multiple quantum transitions. Furthermore, an analogue of nonlinear Landau–Zener tunneling induced by the bias modulation is discussed.