Title: Stable non-Fermi liquid fixed point at the onset of incommensurate $2k_F$ charge density wave order Show Chinese title

Title: 在非共格$2k_F$电荷密度波序开始时的稳定非费米液体固定点

Abstract: We consider the emergence of a non-Fermi liquid fixed point in a two-dimensional metal, at the onset of a quantum phase transition from a Fermi liquid state to an incommensurate charge density wave (CDW) ordered phase. The momentum of the CDW boson is centred at the wavevector $ \boldsymbol{ \mathcal Q} $, which connects a single pair of antipodal points on the Fermi surface with antiparallel tangent vectors. We employ the dimensional regularization technique in which the co-dimension of the Fermi surface is extended to a generic value, while keeping the dimension of the Fermi surface itself fixed at one. Although the system is strongly coupled at dimension $d=2$, the interactions become marginal at the upper critical dimension $d=d_c$, whose value is found to be $ 5/2$. Using a controlled perturbative expansion in the parameter $\epsilon = d_c - d $, we compute the critical exponents of the stable infrared fixed point characterizing the quantum critical point. The scalings of the original theory are determined by setting $\epsilon =1/2$, where the fermion self-energy is seen to scale with the frequency with a fractional power law of $2/3$, which is the telltale signature of a typical non-Fermi liquid phase. Show Chinese abstract

Abstract: 我们考虑在二维金属中出现非费米液体固定点，这是从费米液体状态到不共线电荷密度波（CDW）有序相的量子相变开始时的现象。 CDW玻色子的动量集中在波矢$ \boldsymbol{ \mathcal Q} $上，该波矢连接费米面上的一对相对点，并具有反平行的切向量。 我们采用维数正则化技术，其中费米面的余维数被扩展到一个通用值，同时保持费米面本身的维度固定为一。 尽管系统在维度$d=2$处是强耦合的，但在上临界维度$d=d_c$处相互作用变得边缘，其值被发现为$ 5/2$。 通过参数$\epsilon = d_c - d $的受控微扰展开，我们计算了表征量子临界点的稳定红外固定点的临界指数。 原始理论的标度由设置$\epsilon =1/2$确定，其中费米子自能被看到与频率呈分数幂律的标度，其幂指数为$2/3$，这是典型非费米液体相的特征标志。