Erratum: “Field-Induced Two-Step Phase Transitions in the Singlet Ground State Triangular Antiferromagnet CsFeBr₃”

Magnetic-field- and pressure-induced quantum phase transition inCsFeCl3proved via magnetization measurements

“…within the mean field theory [46]. Using D/k B = 25.3 K, J 0 /k B = 5.27 K, and J 1 /k B = 0.28 K determined at am- bient pressure [33] and g = 2.54 [54], we obtain H c = ∆/g µ B = 4.73 T, which is consistent with H c = 3.6 T evaluated in the present work.…”

Universality of magnetic-field-induced Bose-Einstein condensation of magnons

“…In a previous specific heat study by a relaxation method [33], a two-step anomaly was observed in highfields for H c. This implied the presence of an exotic intermediate state in CsFeBr 3 . After the measurement, however, we noticed that some of the thin metal wires which loosely hook a sample platform were disconnected or had loosened.…”

“…For these reasons, CsFeBr 3 is advantageous for precise verification of the universality of 3D magnon BEC. Although CsFeBr 3 has long been known to exhibit a magnetic-field-induced AF ordering [34], little attentions has been paid to its lowtemperature quantum critical phenomena except in our previous report [33].…”

“…Single crystals of CsFeBr 3 were grown by the vertical Bridgman method from a melt of a stoichiometric mixture of the constituent elements sealed in an evacuated quartz tube [33]. The quartz tube was lowered in the vertical direction at a rate of 3 mm/h from the center of the furnace, the temperature of which was regulated at 540 • C. After the removal of impurities and imperfect crystals, we repeated the same procedure.…”

“…CsFeBr 3 undergoes a magnetic ordering corresponding to magnon BEC when subjected to an external magnetic field parallel to the c axis. The spin configuration in the ordered state above H c ∼ 3 T [33] is the canted 120 • structure characteristic of a triangular lattice antiferromagnet [34].…”