Quantum spin liquids by geometric lattice design

Abstract

On a lattice composed of triangular plaquettes where antiferromagnetic exchange interactions between localized spins cannot be simultaneously satisfied, the system becomes geometrically frustrated with magnetically disordered phases remarkably different from a simple paramagnet. Spin liquid belongs to one of these exotic states, in which a macroscopic degeneracy of the ground state gives rise to the rich spectrum of collective phenomena. Here, we report on the discovery of a new magnetic state in the heterostructures derived from a single unit cell (111)-oriented spinel CoCr2O4 sandwiched between nonmagnetic Al2O3 spacers. The artificial quasi-two-dimensional material composed of three triangle and one kagome atomic planes shows a degree of magnetic frustration which is almost two orders of magnitude enlarged compared to the bulk crystals. Combined resonant X-ray absorption and torque magnetometry measurements confirm that the designer system exhibits no sign of spin ordering down to 30 mK, implying a possible realization of a quantum spin liquid state in the two dimensional limit.

References in corpus (9)

• Quantum Spin Liquid States
• Coexistence of Magnetic Order and Two-dimensional Superconductivity at LaAlO${}_3$/SrTiO${}_3$ Interfaces
• Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2
• Spin-Liquid State in the S = 1/2 Hyperkagome Antiferromagnet Na4Ir3O8
• Thermal Hall conductivity in the frustrated pyrochlore magnet Tb2Ti2O7
• Spin-induced symmetry breaking in orbitally ordered NiCr_2O_4 and CuCr_2O_4
• Unconventional magnetostructural transition in CoCr2O4 at high magnetic fields
• Mott Electrons in an Artificial Graphenelike Crystal of Rare-Earth Nickelate
• Epitaxial Growth of (1 1 1)-Oriented Spinel CoCr${}_2$O${}_4$/Al${}_2$O${}_3$ Heterostructures

Cited by in corpus (1)

• Orientation-dependent stabilization of MgCr${}_2$O${}_4$ spinel thin films