Lee S-S B, Park Jinhong, Sim H-S
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Phys Rev Lett. 2015 Feb 6;114(5):057203. doi: 10.1103/PhysRevLett.114.057203. Epub 2015 Feb 4.
We propose a variational approach for computing the macroscopic entanglement in a many-body mixed state, based on entanglement witness operators, and compute the entanglement of formation (EoF), a mixed-state generalization of the entanglement entropy, in single- and two-channel Kondo systems at finite temperature. The thermal suppression of the EoF obeys power-law scaling at low temperature. The scaling exponent is halved from the single- to the two-channel system, which is attributed, using a bosonization method, to the non-Fermi liquid behavior of a Majorana fermion, a "half" of a complex fermion, emerging in the two-channel system. Moreover, the EoF characterizes the size and power-law tail of the Kondo screening cloud of the single-channel system.
我们基于纠缠见证算符提出了一种变分方法，用于计算多体混合态中的宏观纠缠，并在有限温度下计算了单通道和双通道近藤系统中形成纠缠（EoF），它是纠缠熵的混合态推广形式。在低温下，EoF的热抑制遵循幂律标度。标度指数从单通道系统到双通道系统减半，使用玻色化方法可知，这归因于双通道系统中出现的马约拉纳费米子（复费米子的“一半”）的非费米液体行为。此外，EoF表征了单通道系统近藤屏蔽云的大小和幂律尾部。
