M B Stone et al 2007 New J. Phys. 9 31 doi:10.1088/1367-2630/9/2/031
Field-driven phase transitions in a quasi-two-dimensional quantum antiferromagnet
Focus on Correlated Electrons, Magnetism and Superconductivity in High Magnetic FieldsM B Stone1,2,3,7, C Broholm2,4, D H Reich2, P Schiffer3, O Tchernyshyov2, P Vorderwisch5 and N Harrison6
Show affiliationsPart of Focus on Correlated Electrons, Magnetism and Superconductivity in High Magnetic Fields
We report magnetic susceptibility, specific heat, and neutron scattering measurements as a function of applied magnetic field and temperature to characterize the S = 1/2 quasi-two-dimensional (2D) frustrated magnet piperazinium hexachlorodicuprate (PHCC). The experiments reveal four distinct phases. At low temperatures and fields the material forms a quantum paramagnet with a 1 meV singlet triplet gap and a magnon bandwidth of 1.7 meV. The singlet state involves multiple spin pairs some of which have negative ground state bond energies. Increasing the field at low temperatures induces 3D long-range antiferromagnetic order at 7.5 Tesla through a continuous phase transition that can be described as magnon Bose–Einstein condensation. The phase transition to a fully polarized ferromagnetic state occurs at 37 Tesla. The ordered antiferromagnetic phase is surrounded by a renormalized classical region. The crossover to this phase from the quantum paramagnet is marked by a distinct anomaly in the magnetic susceptibility which coincides with closure of the finite temperature singlet–triplet pseudo gap. The phase boundary between the quantum paramagnet and the Bose–Einstein condensate features a finite temperature minimum at T = 0.2 K, which may be associated with coupling to nuclear spin or lattice degrees of freedom close to quantum criticality.
- PACS
-
75.30.Kz Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.)
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
- Subjects
- Dates
-
Issue 2 (February 2007)
Received 16 November 2006
Published 16 February 2007
-
Field-driven phase transitions in a quasi-two-dimensional quantum antiferromagnet
M B Stone et al 2007 New J. Phys. 9 31
-
A technique for the measurement of 'sucking' in bottle fed infants
T Drake and A J Wilson 1983 Clin. Phys. Physiol. Meas. 4 343
-
EPR investigation of krohnkite, Na2Cu(SO4)2.2H2O
C R N Sarma et al 1976 J. Phys. C: Solid State Phys. 9 841
-
Ferroelastic phase transition in the sanmartinite (ZnWO4)-cuproscheelite (CuWO4) solid solution
P F Schofield and S A T Redfern 1992 J. Phys.: Condens. Matter 4 375
-
Mica windows for electronographic image tubes
J D McGee and D McMullan 1969 J. Phys. E: Sci. Instrum. 2 36
-
Precise determination of the neutral Higgs boson masses in the MSSM
Benjamin C. Allanach et al JHEP09(2004)044
-
How to compute loop corrections to the Bethe approximation
Andrea Montanari and Tommaso Rizzo J. Stat. Mech. (2005) P10011
-
The random-variable canonical distribution
L E Beghian and E Sheldon 2001 J. Phys. A: Math. Gen. 34 2913
-
Impurity effects on energy levels and far-infrared spectra of nanorings
Pan Hui and Zhu Jia-Lin 2003 J. Phys.: Condens. Matter 15 7287
-
Algebraic approach to quantum field theory on non-globally-hyperbolic spacetimes
Ulvi Yurtsever 1994 Class. Quantum Grav. 11 999
Users also read
What's this?Related review articles
What's this?- Itinerant helimagnet MnSi
- Surface spin-flop transition in an antiferromagnet
- Magnetic anisotropy, exchange and damping in cobalt-based full-Heusler compounds: an experimental review