Work

Emergent D 8 ( 1 ) spectrum and topological soliton excitation in CoNb 2 O 6

Year: 2025

Type: article

Abstract: Quantum integrability emerging near a quantum critical point (QCP) is manifested by an exotic excitation spectrum that is organized by the associated algebraic structure. A well-known example is the emergent ${E}_{8}$ integrability near the QCP of a transverse field Ising chain (TFIC), which was long predicted theoretically and initially proposed to be realized in the quasi-one-dimensional (q1D) quantum magnet ${\mathrm{CoNb}}_{2}{\mathrm{O}}_{6}$. However, later measurements on the spin excitation spectrum of this material revealed a series of satellite peaks in low energies that go beyond the description of the ${E}_{8}$ Lie algebra. Motivated by this experimental progress, we hereby revisit the spin excitations of ${\mathrm{CoNb}}_{2}{\mathrm{O}}_{6}$ by combining numerical calculation and analytical analysis. We show that, as effects of strong interchain fluctuations, the spectrum of the system near the 1D QCP is characterized by an emergent ${D}_{8}^{(1)}$ Lie algebra instead of the ${E}_{8}$ one. We further show that the ${D}_{8}^{(1)}$ spectrum can be realized in a broad class of interacting quantum systems. Our results advance the exploration and manipulation of integrability in quantum critical systems.

Source: Physical review. B./Physical review. B

DOI: 10.1103/f32m-kkzm

Authors: Ning Xi, Xiao Wang, Yunjing Gao, Yunfeng Jiang, Rong Yu, Jianda Wu