Robust orbital diamagnetism in correlated Dirac fermions
Robust orbital diamagnetism in correlated Dirac fermions
复制标题
相关狄拉克费米子中的鲁棒轨道抗磁性
DOI：
10.1088/1367-2630/ac8e8e
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发表时间：
2022
影响因子：
3.3
通讯作者：
Yasuhiro Tada
中科院分区：
文献类型：
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作者：
Hidaka Yuichiro;Furuya Shunsuke C.;Ueda Atsushi;Tada Yasuhiro;Yasuhiro Tada
研究了零温下具有短程相互作用的（2+ 1）维狄拉克费米子的轨道抗磁性，这种相互作用表现出从量子相变到电荷密度波（CDW）相的过程。在π通量正方晶格上的无自旋狄拉克费米子中引入轨道磁场，并利用无限密度矩阵重整化群对其进行分析.结果表明，在狄拉克半金属区，抗磁性保持不变，而在CDW区，抗磁性受到单调抑制。在CDW相变的量子临界点附近，我们发现了手征伊辛普适类的抗磁性特征的标度行为。此外，标度分析表明，只要标度区域足够宽，狄拉克半金属体系在弱磁场下的轨道抗磁性不仅在我们的模型中成立，而且在其他相互作用狄拉克费米子体系中也成立.标度行为也可以被视为临界卡西米尔效应的量子磁性模拟，卡西米尔效应已被广泛研究用于经典相变。
We study orbital diamagnetism at zero temperature in (2+ 1)-dimensional Dirac fermions with a short-range interaction which exhibits a quantum phase transition to a charge density wave (CDW) phase. We introduce orbital magnetic fields into spinless Dirac fermions on the π-flux square lattice, and analyze them by using infinite density matrix renormalization group. It is found that the diamagnetism remains intact in the Dirac semimetal regime, while it is monotonically suppressed in the CDW regime. Around the quantum critical point of the CDW phase transition, we find a scaling behavior of the diamagnetism characteristic of the chiral Ising universality class. Besides, the scaling analysis implies that the robust orbital diamagnetism at weak magnetic fields in a Dirac semimetal regime would hold not only in our model but also in other interacting Dirac fermion systems as long as scaling regions are wide enough. The scaling behavior may also be regarded as a quantum, magnetic analogue of the critical Casimir effect which has been widely studied for classical phase transitions.