Multi-crossing problem and Landau Zener scenario: controlled quantum bit

Abstract

The paper investigates multi-crossing dynamics of two-level Landau Zener (LZ) systems applying Dynamic matrix approach (DMA) and shows the two-level (multi-crossing) model to tailor qubits. The paper derives the probabilities for different multi-crossing problems and finds the possible parameters tailoring qubits. Particulary we investigate a variant of the Landau-Zener problem in which the coupling between the adiabatic levels is induced by an ac field, i.e., the energy level or tunnel coupling oscillates. We consider two limits, namely fast and slow driving in which the transition probability found exact analytical solution and derive the resonance condition for frequencies.