K. Mishima

Effect of quantum interference on tunneling photoionization rates of N2 and O2 molecules

In this work, we reexamine the photoionization rates of N(2) and O(2) molecules using the previously published photoionization rate theory which is based on the original atomic Keldysh theory [K. Mishima et al., Phys. Rev. A 66, 033401 (2002); ibid.66, 053408 (2002)]. We have found that the constructive quantum interference takes place for N(2) molecule while the destructive quantum interference plays an important role for O(2) molecule. This is consistent with the experimental and theoretical results reported in the literature. The formulas derived in this paper clearly show that this is due to the different symmetries of the valence orbitals of N(2) and O(2) molecules.

Coherence control between two quantum systems using spatial phase

Abstract In this Letter, we investigate new method of generating and controlling quantum coherences between two two-level quantum systems by using the spatial phase of one single-mode incident laser pulse. We take two identical semiconductor quantum dots as an illustration. Our method is to use the spatial phase of the laser pulse at the different positions of the quantum systems for the operations similar to two-qubit operations in the quantum computer language, rather than to employ the frequently used dipole–dipole interactions between them. In the present Letter, a specific operation similar to two-qubit quantum operation is examined numerically. Our investigation demonstrates that the spatial phase will also be useful for quantum operations.

Towards the realization of the quantum chemistry approach to tunneling photoionization processes in strong laser fields

Based on Keldyshs theory, we investigate the possibility to use the molecular orbital theoretic approach for calculating the tunneling photoionization rates of molecules. As a demonstration, we concentrate on the 1s state of the hydrogen atom as the initial state.

High temperature effect on photo-induced electron transfer

Anharmonicity plays a very important role in the high temperature range for photo-induced electron transfer. A simple truncated oscillator model is used to investigate the effect of the disallowed states of anharmonicity on the photo-induced electron transfer. The obtained formula shows that in the high temperature limit, the electron transfer rate becomes a constant, independent of temperature, but the Marcus equation approaches zero.