Experimental Verification of the Universality of Magnetic-Field-Induced Bose-Einstein Condensation of Magnons

Abstract

CsFeBr${}_3$ is an $S=1$ hexagonal antiferromagnet that has a singlet ground state owing to its large easy-plane single-ion anisotropy. The critical behavior of the magnetic-field-induced phase transition for a magnetic field parallel to the $c$ axis, which can be described by the Bose-Einstein condensation (BEC) of magnons under the $U(1)$ symmetry, was investigated via magnetization and specific heat measurements down to 0.1K. For the specific heat measurement, we have developed a method of effectively suppressing the torque acting on a sample with strong anisotropy that uses the spin dimer compound Ba${}_2$CoSi${}_2$O${}_6$Cl${}_2$ with large and anisotropic Van Vleck paramagnetism. The temperature dependence of the transition field $H_{\mathrm{c}}(T)$ was found to follow the power-law $H_{\mathrm{c}}(T)-H_{\mathrm{c}}\propto T^{\varphi }$ with a critical exponent of $\varphi =1.50\pm 0.02$ and critical field of $H_{\mathrm{c}}=2.60$ T. This result verifies the universality of the three-dimensional BEC of magnons described by ${\varphi }_{\mathrm{BEC}}=3/2$.

5 pages, 3 figures, to appear in Phys. Rev. B

References in corpus (8)

• Bose-Einstein Condensation in Magnetic Insulators
• A direct measurement of the Bose-Einstein Condensation universality class in NiCl${}_2$-4SC(NH${}_2$)${}_2$ at ultra-low temperatures
• Magnetic-field- and pressure-induced quantum phase transition in CsFeCl${}_3$ proved via magnetization measurement
• Almost Perfect Frustration in the Dimer Magnet Ba${}_2$CoSi${}_2$O${}_6$Cl${}_2$
• U(1)-Symmetry breaking and violation of axial symmetry in TlCuCl3 and other insulating spin systems
• Nuclear magnetic resonance study of the magnetic-field-induced ordered phase in the NiCl2-4SC(NH2)2 compound
• Critical exponents and intrinsic broadening of the field-induced transition in NiCl${}_2$$\cdot$4SC(NH${}_2$)${}_2$
• Giant dielectric nonlinearities at a magnetic Bose-Einstein condensation

Cited by in corpus (3)

• Spin Seebeck effect in quantum magnet Pb2V3O9
• Field-induced Bose-Einstein condensation and supersolid in the two-dimensional Kondo necklace
• Magnetic field-driven transition between valence bond solid and antiferromagnetic order in distorted triangular lattice