Deconfined quantum phase transition on the kagome lattice: Distinct velocities of spinon and string excitations

Abstract

Deconfined quantum phase transition (DQPT) provides an extraordinary possibility of the quantum phase transition beyond the Ginzburg-Landau paradigm, which is interwoven with numerous exotic phenomena of the strongly correlated quantum many-body system, e.g. fractional excitation, emergent symmetries, and gauge field. However, various candidates of DQPT have been demonstrated to be weakly first-order, and the conformal field theory (CFT) has to be altered into a non-unitary one. Here we numerically found two linear dispersions with different velocities in one of the few survivors of DQPT -- the extended hard-core Bose-Hubbard model on the Kagome lattice. Such counterintuitive results directly lead to the negation of possible emergent Lorentz symmetry, and the breakdown of conventional theory of DQPT. Furthermore, the snapshots of boson configuration hint that these two velocities may correspond to the dynamics of the fractional excitations and quantum strings, respectively. Our work will inspire the revisit of the theory of DQPT and benefit the field of quantum materials and quantum simulations.

6 pages, 8 figures, almost published version, comments are welcome, and more information at http://cqutp.org/users/xfzhang/

References in corpus (16)

• "Deconfined" quantum critical points
• Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
• Evidence for deconfined quantum criticality in a two-dimensional Heisenberg model with four-spin interactions
• Generalized Symmetries in Condensed Matter
• Probing spin-charge separation in a Tomonaga-Luttinger liquid
• Valence Bond Solids and Their Quantum Melting in Hard-Core Bosons on the Kagome Lattice
• Nearly deconfined spinon excitations in the square-lattice spin-1/2 Heisenberg antiferromagnet
• Duality between the deconfined quantum-critical point and the bosonic topological transition
• Progress on stochastic analytic continuation of quantum Monte Carlo data
• Spin nematics and magnetization plateau transition in anisotropic Kagome magnets
• Proximate deconfined quantum critical point in SrCu2(BO3)2
• Realizing distance-selective interactions in a Rydberg-dressed atom array
• Scaling of disorder operator at deconfined quantum criticality
• Fermion disorder operator at Gross-Neveu and deconfined quantum criticalities
• Quantum dynamics of topological strings in a frustrated Ising antiferromagnet
• Frozen deconfined quantum criticality

Cited by in corpus (4)

• Deconfined Quantum Critical Point: A Review of Progress
• Frustrated Rydberg Atom Arrays Meet Cavity-QED: Emergence of the Superradiant Clock Phase
• Loop Algorithm for Quantum Transverse Ising Model in a Longitudinal Field
• Quantum colored strings in the hole-doped $t$-$J_z$ model