- Journal Article
Rights / licenseCreative Commons Attribution 4.0 International
Magnetic-field-induced phase transitions are investigated in the frustrated gapped quantum paramagnet Rb2Cu2Mo3O12 through dielectric and calorimetric measurements on single-crystal samples. It is clarified that the previously reported dielectric anomaly at 8 K in powder samples is not due to a chiral spin liquid state as has been suggested, but rather to a tiny amount of a ferroelectric impurity phase. Two field-induced quantum phase transitions between paraelectric and paramagnetic and ferroelectric and magnetically ordered states are clearly observed. It is shown that the electric polarization is a secondary order parameter at the lower-field (gap closure) quantum critical point but a primary one at the saturation transition. Having clearly identified the magnetic Bose-Einstein condensation (BEC) nature of the latter, we use the dielectric channel to directly measure the critical divergence of BEC susceptibility. The observed power-law behavior is in very good agreement with theoretical expectations for three-dimensional BEC. Finally, dielectric data reveal magnetic presaturation phases in this compound that may feature exotic order with unconventional broken symmetries. Show more
Journal / seriesPhysical Review Research
Pages / Article No.
PublisherAmerican Physical Society
Organisational unit03855 - Zheludev, Andrey / Zheludev, Andrey
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