<p>Quantum fluctuations endow spin systems with surprisingly enriched magnetic phase diagrams. In frustrated magnets, strong quantum fluctuations boosted by either geometrical incompatibility or competitive exchange interactions stabilize cascades of unusual phases of matter. Here we reveal the presence of multiple quantum phases in the honeycomb antiferromagnet Na<sub>3</sub>Ni<sub>2</sub>BiO<sub>6</sub>, both inside and beyond its field-induced one-third magnetization plateau. Comprehensive measurements of thermodynamic quantities demonstrate that the one-third plateau comprises at least three distinct spin states with nearly-degenerate net magnetization, separated by first-order transitions that likely involve sequential spin reconfiguration. Upon further increasing the magnetic field, the system evolves across a myriad of peculiar phases before reaching full polarization; these intermediate phases possess copious low-energy excitations, manifested by anomalous upturns of specific heat at ultralow temperatures — probably hinting at the development of “hidden” ordered ground states. The complex magnetic phase diagram of Na<sub>3</sub>Ni<sub>2</sub>BiO<sub>6</sub> underlines the preponderant impact of quantum fluctuations on a honeycomb spin lattice with strong exchange frustration.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Cascade of magnetic-field-induced quantum spin states in a spin-1 honeycomb magnet

  • Kaixin Tang,
  • Zhao-Yang Dong,
  • Yanyan Shangguan,
  • Zhao Gong,
  • Ye Yang,
  • Song Bao,
  • Houpu Li,
  • Nan Zhang,
  • Hongyu Li,
  • Jian-Xin Li,
  • Jinsheng Wen,
  • Ziji Xiang,
  • Xianhui Chen

摘要

Quantum fluctuations endow spin systems with surprisingly enriched magnetic phase diagrams. In frustrated magnets, strong quantum fluctuations boosted by either geometrical incompatibility or competitive exchange interactions stabilize cascades of unusual phases of matter. Here we reveal the presence of multiple quantum phases in the honeycomb antiferromagnet Na3Ni2BiO6, both inside and beyond its field-induced one-third magnetization plateau. Comprehensive measurements of thermodynamic quantities demonstrate that the one-third plateau comprises at least three distinct spin states with nearly-degenerate net magnetization, separated by first-order transitions that likely involve sequential spin reconfiguration. Upon further increasing the magnetic field, the system evolves across a myriad of peculiar phases before reaching full polarization; these intermediate phases possess copious low-energy excitations, manifested by anomalous upturns of specific heat at ultralow temperatures — probably hinting at the development of “hidden” ordered ground states. The complex magnetic phase diagram of Na3Ni2BiO6 underlines the preponderant impact of quantum fluctuations on a honeycomb spin lattice with strong exchange frustration.