arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0811.4579cond-mat.str-el
收藏

临界二子带量子线中速度为零的突现Lorentz对称性

Emergent Lorentz symmetry with vanishing velocity in a critical two-subband quantum wire

M. Sitte, A. Rosch, J. S. Meyer, K. A. Matveev, M. Garst

摘要:

本文研究了在强相互作用下具有两个自旋极化电子子带的量子线。我们专注于量子相变时,第二子带开始得到作为栅极电压的函数填充。通过对有效哈密顿量进行单圈重整化群(RG)分析,我们将临界不动点理论确定为具有增强的SU(2)对称性和中心荷3/2的共形场论。虽然固定点是洛伦兹不变的,但由于稍微不相关的算子导致临界比热系数发散,有效的“光速”在低能量下消失。

英文摘要:

We consider a quantum wire with two subbands of spin-polarized electrons in the presence of strong interactions. We focus on the quantum phase transition when the second subband starts to get filled as a function of gate voltage. Performing a one-loop renormalization group (RG) analysis of the effective Hamiltonian, we identify the critical fixed-point theory as a conformal field theory having an enhanced SU(2) symmetry and central charge 3/2. While the fixed point is Lorentz invariant, the effective 'speed of light' nevertheless vanishes at low energies due to marginally irrelevant operators leading to a diverging critical specific heat coefficient.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑