Extended Two-Channel Kondo Phase of a Rotational Quantum Defect in a Fermi Gas

27th International Conference on Low Temperature Physics

Chuo, E. Fuh^1 ; Ballmann, K.^1 ; Borda, L.^2 ; Kroha, J.^1

Physikalisches Institut, Universität Bonn, Nussallee 12, Bonn

53115, Germany^1

Department of Theoretical Physics, Budapest University of Technology and Economics, Budafoki ut 8, Budapest

H-1111, Hungary^2

关键词: Correlation effect;    Lowest energy state;    Momentum scattering;    Numerical renormalization groups;    Quantum defects;    Rotational degree of freedom;    Temperature dependent;    Without fine-tuning;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/568/1/012007/pdf
DOI  :  10.1088/1742-6596/568/1/012007

来源: IOP

【 摘 要 】

We show by numerical renormalization group calculations that a quantum defect with a two-dimensional rotational degree of freedom, immersed in a bath of fermionic particles with angular momentum scattering, exhibits an extended 2CK phase without fine-tuning of parameters. It is stabilized by a correlation effect which causes the states with angular momentum m=±1 to be the lowest energy states of the defect. This level crossing with the noninteracting m 0 ground state is signaled by a plateau in the temperature-dependent impurity entropy at S(T) kBln 2, before the 2CK ground state value S(0) kBIn is reached.