Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2009-07-30
Phys. Rev. B 80, 165113 (2009)
Physics
Condensed Matter
Strongly Correlated Electrons
26 pages, 31 figures. Added references and corrected typos
Scientific paper
We study the competition between Kondo physics and dissipation within an Anderson model of a magnetic impurity level that hybridizes with a metallic host and is also coupled, via the impurity charge, to the displacement of a bosonic bath having a spectral density proportional to \omega^s. As the impurity-bath coupling increases from zero, the effective Coulomb interaction between two electrons in the impurity level is progressively renormalized from its repulsive bare value until it eventually becomes attractive. For weak hybridization, this renormalization in turn produces a crossover from a conventional, spin-sector Kondo effect to a charge Kondo effect. At particle-hole symmetry, and for sub-Ohmic bath exponents 0 < s < 1, further increase of the impurity-bath coupling results in a continuous, zero-temperature transition to a broken-symmetry phase in which the ground-state impurity occupancy \n_d acquires an expectation value <\n_d>_0 \ne 1. The response of the impurity occupancy to a locally applied electric potential features the hyperscaling of critical exponents and \omega/T scaling that are expected at an interacting critical point. The numerical values of the critical exponents suggest that the transition lies in the same universality class as that of the sub-Ohmic spin-boson model. For the Ohmic case s = 1, the transition is instead of Kosterlitz-Thouless type. Away from particle-hole symmetry, the quantum phase transition is replaced by a smooth crossover, but signatures of the symmetric quantum critical point remain in the physical properties at elevated temperatures and/or frequencies.
Cheng Mengxing
Glossop Matthew T.
Ingersent Kevin
No associations
LandOfFree
Quantum phase transitions in a charge-coupled Bose-Fermi Anderson model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Quantum phase transitions in a charge-coupled Bose-Fermi Anderson model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantum phase transitions in a charge-coupled Bose-Fermi Anderson model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-469332