Spin waves and quantum criticality in the frustrated XY pyrochlore antiferromagnet Er2Ti2O7 |
| |
Authors: | Ruff J P C Clancy J P Bourque A White M A Ramazanoglu M Gardner J S Qiu Y Copley J R D Johnson M B Dabkowska H A Gaulin B D |
| |
Institution: | Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada. |
| |
Abstract: | We report detailed measurements of the low temperature magnetic phase diagram of Er2Ti2O7. Heat capacity and time-of-flight neutron scattering studies of single crystals reveal unconventional low-energy states. Er3+ magnetic ions reside on a pyrochlore lattice in Er2Ti2O7, where local XY anisotropy and antiferromagnetic interactions give rise to a unique frustrated system. In zero field, the ground state exhibits coexisting short and long-range order, accompanied by soft collective spin excitations previously believed to be absent. The application of finite magnetic fields tunes the ground state continuously through a landscape of noncollinear phases, divided by a zero temperature phase transition at micro{0}H{c} approximately 1.5 T. The characteristic energy scale for spin fluctuations is seen to vanish at the critical point, as expected for a second order quantum phase transition driven by quantum fluctuations. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|