Allen Scheie1,Esteban Ghioldi2,3,Jie Xing1,Joseph Paddison1,Nick Sherman4,5,Maxime Dupont5,4,Douglas Abernathy1,Daniel Pajerowski1,Shang-Shun Zhang6,L. O. Manuel3,A. E. Trumper3,Chaitanya Das Pemmaraju7,Athena Sefat1,David Parker1,Thomas Devereaux7,Joel Moore4,Christian Batista2,D. Alan Tennant1,2
Oak Ridge National Laboratory1,The University of Tennessee, Knoxville2,Instituto de física Rosario3,University of California, Berkeley4,Lawrence Berkeley National Laboratory5,University of Minnesota6,Stanford University7
Allen Scheie1,Esteban Ghioldi2,3,Jie Xing1,Joseph Paddison1,Nick Sherman4,5,Maxime Dupont5,4,Douglas Abernathy1,Daniel Pajerowski1,Shang-Shun Zhang6,L. O. Manuel3,A. E. Trumper3,Chaitanya Das Pemmaraju7,Athena Sefat1,David Parker1,Thomas Devereaux7,Joel Moore4,Christian Batista2,D. Alan Tennant1,2
Oak Ridge National Laboratory1,The University of Tennessee, Knoxville2,Instituto de física Rosario3,University of California, Berkeley4,Lawrence Berkeley National Laboratory5,University of Minnesota6,Stanford University7
We report the inelastic neutron spectrum of 2D triangular lattice KYbSe<sub>2</sub>, and show proximity to a quantum spin liquid phase. We apply entanglement witnesses [1] to 2D KYbSe<sub>2</sub> neutron scattering, and show evidence of an entangled ground state. Fitting the high-temperature paramagnetic scattering shows the magnetic exchange Hamiltonian approximates the quantum triangular lattice J<sub>1</sub>-J<sub>2</sub> model. Although the system orders at the lowest temperatures with 120° order, comparison to Schwinger boson and DMRG simulations shows the KYbSe<sub>2</sub> excitations strongly resemble a 2D quantum spin liquid. At finite temperatures we observe quantum critical scaling, which indicates proximity to a deconfined spin liquid phase, and also sheds light on the nearby quantum spin liquid state.<br/>[1] Scheie, Laruell et al, Phys. Rev. B 103, 224434 (2021)<br/>[2] Scheie et al, ArXiv:2109.11527 (2021)