Entanglement and Criticality in Quantum Impurity Systems
Abstrak
We investigate the entanglement between a spin and its environment in impurity systems which exhibit a second-order quantum phase transition. As an application, we employ the spin-boson model, describing a two-level system (spin) coupled to a subohmic bosonic bath with power-law spectral density, ${\cal J}(ω)\propto ω^s$ and $0<s<1$. Combining Wilson's Numerical Renormalization Group method and hyperscaling relations, we demonstrate that the entanglement between the spin and its environment is always enhanced at the quantum phase transition resulting in a visible cusp (maximum) in the entropy of entanglement. We formulate a correspondence between criticality and impurity entanglement entropy, and the relevance of these ideas to Nano-systems is outlined.
Topik & Kata Kunci
Penulis (3)
Karyn Le Hur
Philippe Doucet-Beaupre
Walter Hofstetter
Akses Cepat
- Tahun Terbit
- 2007
- Bahasa
- en
- Sumber Database
- arXiv
- Akses
- Open Access ✓