The Hidden order in URu2Si2 is is one of the mysteries of strongly correlated electron materials.
Indeed, after several decades of intense investigations, the microscopic origin of this ordered state has not been identified with certainty.
The theoretical work presented in this talk is motivated by the search for a spin-liquid scenario for the hidden order.
In a first part, we describe a Modulated Spin Liquid scenario on a square lattice, using Kondo plus Heisenberg mode, showing how a spin liquid paramagnetic state breaking lattice translation can be formed in a strongly correlated metalic system. Then, we study a generalization of the quantum Heisenberg model in a lattice which is more realistic for URu2Si2: the geometrically frustrated body-centered tretragonal (BCT) lattice with antiferromagnetic interlayer coupling J1 and intralayer first and second neighbor coupling J2 and J3. Using two different descriptions of spin operators (a large degeneracy limiti and a large spin limit), we analyze the phase diagram characterizing the ground state of the system.
We show that spin-liquid solutions can be stabilized, that break the lattice translation symmetry. Also, we show how competition between J1, J2, and J3 can tune the ground state from a magnetically ordered to a spin liquid state.
We then propose an effective model to describe the Raman scattering experiments in crystalline materials with BCT lattice.
Our model takes into account different (modulated or chiral) emerging spin liquid states, associated with different point group symmetries. We analize some signatures of these states and we discuss the relevance of this scenario for correlated systems with BCT crystal structure.
Références
- C. Pépin, M.R. Norman, S. Burdin, A. Ferraz, Phys. Rev. Lett. 106, 106601 (2011)
- C. Thomas, S. Burdin, C. Pépin, A. Ferraz, Phys. Rev. B 87, 014422 (2013)
- X. Montiel, S. Burdin, C. Pépin, A. Ferraz, Phys. Rev. B 90, 045125 (2014)
- C. Farias, C. Thomas, C. Pépin, A. Ferraz, C. Lacroix, S. Burdin, Phys. Rev. B 94, 134420 (2016)
- C. Farias, M.-A. Méasson, A. Ferraz, S. Burdin, Phys. Rev. B 101, 205114 (2020)
Laboratoire Ondes et Matière d’Aquitaine