Tomonaga–Luttinger liquid behavior and spinon confinement in YbAlO3

Abstract

Low dimensional quantum magnets are interesting because of the emerging collective behavior arising from strong quantum fluctuations. The one-dimensional (1D) S = 1/2 Heisenberg antiferromagnet is a paradigmatic example, whose low-energy excitations, known as spinons, carry fractional spin S = 1/2. These fractional modes can be reconfined by the application of a staggered magnetic field. Even though considerable progress has been made in the theoretical understanding of such magnets, experimental realizations of this low-dimensional physics are relatively rare. This is particularly true for rare-earth-based magnets because of the large effective spin anisotropy induced by the combination of strong spin–orbit coupling and crystal field splitting. Here, we demonstrate that the rare-earth perovskite YbAlO3 provides a realization of a quantum spin S = 1/2 chain material exhibiting both quantum critical Tomonaga–Luttinger liquid behavior and spinon confinement–deconfinement transitions in different regions of magnetic field–temperature phase diagram.

Antiferromagnetic ordering and dipolar interactions of YbAlO3

“…However, whereas longitudinal fluctuations are forbidden in DyScO 3 by a selection rule [13], they are being observed in YbAlO 3 [4]. The ground state wave functions in YbAlO 3 (Eqs.…”

“…Further, this indicates there may exist a quantum critical region between 0.3 ∼ 1.1 T for B a (or 1.0 ∼ 2. 2 T for B b), where the static magnetic order (Ax G y) in the ab-plane is suppressed [4].…”

“…While the second question requires advanced theoretical DFTbased calculations, one can answer the first one by studying * Corresponding author: podlesnyakaa@ornl.gov isostructural YbM O 3 materials with a nonmagnetic ion in M position. To this end, we performed a comprehensive study of YbAlO 3 , and demonstrated that it provides a realization of a quantum spin S = 1/2 chain material exhibiting both quantum critical Tomonaga-Luttinger liquid behavior and spinon confinement-deconfinement transitions in different regions of magnetic field-temperature phase space [4].…”

Low-temperature spin dynamics in the TmFeO3 orthoferrite with a non-Kramers ion

“…However, this is usually in the context of single ion physics, and the crystalline environments may change the electronic properties of the rare-earth ions considerably. Experimental hallmarks of exotic quantum states have been recently reported in a number of Yb-based (4 f 13 ) compounds by the observation of Tomonaga-Luttinger liquid behavior and spinon confinement-deconfinement transitions in YbAlO 3 [13]; spinon continuum and spinon confinement in Yb 2 Pt 2 Pb [14,15] and in the triangular-lattice systems YbMgGaO 4 [16,17]; the quantum dimer magnet state in Yb 2 Si 2 O 7 [18] and a Higgs transition from a magnetic Coulomb liquid to a ferromagnet in Yb 2 Ti 2 O 7 [19]. In the rare-earth orthoferrite YbFeO 3 the Yb magnetic sublattice also exhibits rich quantum spin dynamics [20].…”

“…The quantum states of the ground Kramers doublet, separated by a large energy gap from the first excited state, can be viewed as an effective spin-1/2 [14]. It was predicted and demonstrated experimentally that the magnetic properties at low temperatures and in low magnetic fields can be described by a pseudospin S = 1/2 model [13,14,17,20].…”