Li Mei-Rong, Le Hur Karyn, Hofstetter Walter
Département de Physique and RQMP, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada.
Phys Rev Lett. 2005 Aug 19;95(8):086406. doi: 10.1103/PhysRevLett.95.086406.
We show that the Bose-Fermi Kondo model (BFKM), which may find applicability both to certain dissipative mesoscopic qubit devices and to heavy-fermion systems described by the Kondo lattice model, can be mapped exactly onto the Caldeira-Leggett model. This mapping requires an ohmic bosonic bath and an Ising-type coupling between the latter and the impurity spin. This allows us to conclude unambiguously that there is an emergent Kosterlitz-Thouless quantum phase transition in the BFKM with an ohmic bosonic bath. By applying a bosonic numerical renormalization group approach, we thoroughly probe physical quantities close to the quantum phase transition.
我们表明，玻色-费米近藤模型（BFKM）既适用于某些耗散介观量子比特器件，也适用于由近藤晶格模型描述的重费米子系统，它可以精确映射到卡尔德雷拉-莱格特模型。这种映射需要一个欧姆型玻色子浴以及后者与杂质自旋之间的伊辛型耦合。这使我们能够明确得出结论，在具有欧姆型玻色子浴的BFKM中存在一种涌现的科斯特利茨-索利斯量子相变。通过应用玻色子数值重整化群方法，我们深入探究了接近量子相变的物理量。
