arXiv subjects

Jin-Yun Lin

Publications and source records attributed to Jin-Yun Lin.

3 recordsLinked to original sources

arXiv2025

Fermi Liquid Fixed Point Deformations due to Codimension Two Defects

We show that codimension-two defects in Fermi liquids deform the renormalization group flow via a marginally relevant coupling. The mechanism for generating the flow is distinct from the case of the Kondo problem (codimension-three defects) in that the effective particle-hole asymmetry that leads to the log running is due to the spatial anisotropy generated by the defect. The mechanism for the log generation has a simple geometric explanation which shows that hole fluctuations are suppressed as the incoming momentum is taken to be along the direction of the defect. The RG flow time is shown to scale with the length of the defect. We also show that the dislon, the Goldstone mode localized to the defect, couples in a non-derivative fashion to the bulk fermions and becomes relevant above the dislons' Debye frequency which depends upon the defect tension.

cond-mat.str-el↗

arXiv2025

Ising on $\mathbb{S}^2$ -- The Affine Conjecture

We review the recent construction \cite{brower2024isingmodelmathbbs2} of the 2d Ising model on a triangulated sphere $\mathbb{S}^2$. Surprisingly, this led to a precise map of the lattice couplings to the target geometry in order to reach the conform field theory (CFT) in the continuum limit. For the integrable 2d Ising CFT, the map was found analytically \cite{Brower_2023}. Here we conjecture how this might be generalized. The discrete geometry is implemented by the piecewise flat triangulation introduced by Regge in 1960 for the Einstein Hilbert action \cite{Regge1961GeneralRW}. Then following our Ising example, we posit the existence of a smooth map of lattice couplings in affine parameters consistent with quantum correlators. A sequence of theoretical investigations and numerical simulations are recommended to test this conjecture. They begin with non-integrable CFT's -- the 2d $\phi^4$ theory on $\mathbb{S}^2$; the 3d Ising model on $\mathbb{S}^3$ and $\mathbb{R} \times \mathbb{S}^2$; QED3 on $\mathbb{R} \times \mathbb{S}^{2} $ as an intermediate step to 4d non-Abelian lattice gauge theory on $\mathbb{R} \times \mathbb{S}^3$.

hep-lat↗

arXiv2022

Dispersion Relations for Dislocation Modes and their Sensitivity to the Lattice Structure

In this letter we show that the dispersion relation for the dynamical modes of dislocations ("dislons") in solids is sensitive to the lattice symmetries. In particular, we show that in the IR, the dislon dispersion relation develops a logarithmic dependence on momenta for approximately isotropic lattices whereas for non-isotropic lattices, the linear term dominates. The renormalization group flows for dislocation tension are shown to be distinct for isotropic and anisotropic lattices.

hep-th↗