Polarization qubit phase gate between two far-infrared pulses in three-coupled quantum wells

摘要

The cross-Kerr nonlinearity arising between two far-infrared (FIR) pulses is investigated in a three-coupledquantum- well (TCQW) structure based on intersubband transitions. The results show that the giant Kerr nonlinearity with a relatively large cross-phase-modulation phase shift can be used for realizing polarization quantum phase gate in this TCQW structure. Such a semiconductor system is much more practical than its atomic counterpart because of its flexible design and the wide tunable parameters. This protocol may have potential applications in FIR all-optical switch design and quantum information processing with solid-state materials.