Libersky M, McKenzie R D, Silevitch D M, Stamp P C E, Rosenbaum T F
Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, USA.
Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Phys Rev Lett. 2021 Nov 12;127(20):207202. doi: 10.1103/PhysRevLett.127.207202.
We directly measure the low energy excitation modes of the quantum Ising magnet LiHoF_{4} using microwave spectroscopy. Instead of a single electronic mode, we find a set of collective electronuclear modes, in which the spin-1/2 Ising electronic spins hybridize with the bath of spin-7/2 Ho nuclear spins. The lowest-lying electronuclear mode softens at the approach to the quantum critical point, even in the presence of disorder. This softening is rapidly quenched by a longitudinal magnetic field. Similar electronuclear structures should exist in other spin-based quantum Ising systems.
我们使用微波光谱法直接测量了量子伊辛磁体LiHoF₄的低能激发模式。我们发现的不是单一的电子模式，而是一组集体电子-核模式，其中自旋为1/2的伊辛电子自旋与自旋为7/2的钬核自旋库发生杂化。即使存在无序，最低的电子-核模式在接近量子临界点时也会软化。这种软化会被纵向磁场迅速淬灭。其他基于自旋的量子伊辛系统中应该也存在类似的电子-核结构。
