2018/01/24 by Takahiro Sakurai, Yuki Hirao, Keigo Hijii +5 · 52 citations
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Crystal Structures and Properties #Electron paramagnetic resonance #Excitation #Excited state #Ground state #High-pressure geophysics and materials #Phase transition #Physics of Superconductivity and Magnetism #Quantum phase transition #Resonance (particle physics) #Singlet state #Spin (aerodynamics) #cond-mat.str-el
paper · pdf · open access · doi:10.7566/jpsj.87.033701
published in Journal of the Physical Society of Japan 87(3), 033701 (Physical Society of Japan)
arxiv created 2018/01/24 · openalex publication_date 2018/02/01 · openalex created_date 2018/02/02 · arxiv updated 2018/02/21 · openalex updated_date 2026/08/05
High-pressure and high-field electron spin resonance (ESR) measurements have been performed on a single crystal of the orthogonal-dimer spin system SrCu2(BO3)2. With frequencies below 1 THz, ESR signals associated with transitions from the singlet ground state to the one-triplet excited states and the two-triplet bound state were observed at pressures up to 2.1 GPa. We obtained directly the pressure dependence of the gap energies, finding a clear first-order phase transition at Pc=1.85±0.05 GPa. By comparing this pressure dependence with the calculated excitation energies obtained from an exact diagonalization, we determined the precise pressure dependence for inter- (J') and intra-dimer (J) exchange interactions considering the Dzyaloshinski-Moriya interaction. Thus this system undergoes a first-order quantum phase transition from the dimer singlet phase to a plaquette singlet phase above the ratio (J'/J)c=0.660±0.003.