TY - JOUR
T1 - Magnetic field- and pressure-induced quantum phase transitions in NH 4CuCl3
AU - Fujisawa, Masashi
AU - R., Budhy Kurniawan
AU - Ono, Toshio
AU - Tanaka, Hidekazu
PY - 2005
Y1 - 2005
N2 - Quantum antiferromagnet NH4CuCl3 shows magnetization plateaus at 1/4 and 3/4 of the saturation magnetization. Specific heat measurements at ambient pressure and magnetization measurements under hydrostatic pressure were performed on NH4CuCl3 in magnetic fields. From specific heat measurements, we obtained the detailed magnetic phase diagram below 9 T, which includes the lower edge field H c1 of 1/4 plateau. The phase boundary just below Hc1 can be described by a power low, Hc1 - HN(T) ∝ T φ with φ = 2, where HN(T) is the transition field at temperature T. Magnetic susceptibility measurements under pressure revealed reentrant quantum phase transitions, such that the gapless ground state at zero field changes into gapped state with increasing pressure, and further into gapless state again.
AB - Quantum antiferromagnet NH4CuCl3 shows magnetization plateaus at 1/4 and 3/4 of the saturation magnetization. Specific heat measurements at ambient pressure and magnetization measurements under hydrostatic pressure were performed on NH4CuCl3 in magnetic fields. From specific heat measurements, we obtained the detailed magnetic phase diagram below 9 T, which includes the lower edge field H c1 of 1/4 plateau. The phase boundary just below Hc1 can be described by a power low, Hc1 - HN(T) ∝ T φ with φ = 2, where HN(T) is the transition field at temperature T. Magnetic susceptibility measurements under pressure revealed reentrant quantum phase transitions, such that the gapless ground state at zero field changes into gapped state with increasing pressure, and further into gapless state again.
UR - http://www.scopus.com/inward/record.url?scp=29444442440&partnerID=8YFLogxK
U2 - 10.1143/PTPS.159.241
DO - 10.1143/PTPS.159.241
M3 - Article
AN - SCOPUS:29444442440
VL - 159
SP - 241
EP - 245
JO - Progress of Theoretical Physics
JF - Progress of Theoretical Physics
SN - 0033-068X
ER -