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Ground State of Quantum Jahn-Teller Model: Selftrapping vs Correlated Phonon-assisted Tunneling

E. Majernikova·S. Shpyrko
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Abstract

Ground state of the quantum Jahn-Teller model with broken rotational symmetry was investigated by the variational approach in two cases: a lattice and a local ones. Both cases differ by the way of accounting for the nonlinearity hidden in the reflection-symmetric Hamiltonian. In spite of that the ground state energy in both cases shows the same features: there appear two regions of model parameters governing the ground state: the region of dominating selftrapping modified by the quantum effects and the region of dominating phonon-assisted tunneling (antiselftrapping). In the local case (i) the effect of quantum fluctuations and anharmonicity due to the two-mode correlations is up to two orders larger than contributions due to the reflection effects of two-center wave function; (ii) the variational results for the ground state energy were compared with exact numerical results. The coincidence is the better the more far away from the transition region at the E$\otimes$e symmetry where the variational approach fails.

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E. Majernikova, S. Shpyrko. 2005-10-29. Ground State of Quantum Jahn-Teller Model: Selftrapping vs Correlated Phonon-assisted Tunneling. https://doi.org/10.1016/s0065-3276(03)44042-2

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