Abstract
We show that the quantum phase transition arising in a standard radiation-matter model (Dicke model) belongs to the same universality class as the infinitely coordinated, transverse-field XY model. The effective qubit-qubit exchange interaction is shown to be proportional to the square of the qubit-radiation coupling. A universal finite-size scaling is derived for the corresponding two-qubit entanglement (concurrence) and a size-consistent effective Hamiltonian is proposed for the qubit subsystem.
Original language | English (US) |
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Pages (from-to) | 8-14 |
Number of pages | 7 |
Journal | Europhysics Letters |
Volume | 69 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2005 |
ASJC Scopus subject areas
- Physics and Astronomy(all)