Gomilšek M, Klanjšek M, Žitko R, Pregelj M, Bert F, Mendels P, Li Y, Zhang Q M, Zorko A
Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia.
Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, Cedex, France.
Phys Rev Lett. 2017 Sep 29;119(13):137205. doi: 10.1103/PhysRevLett.119.137205.
The ground state of the quantum kagome antiferromagnet Zn-brochantite, ZnCu_{3}(OH){6}SO{4}, which is one of only a few known spin-liquid (SL) realizations in two or three dimensions, has been described as a gapless SL with a spinon Fermi surface. Employing nuclear magnetic resonance in a broad magnetic-field range down to millikelvin temperatures, we show that in applied magnetic fields this enigmatic state is intrinsically unstable against a SL with a full or a partial gap. A similar instability of the gapless Fermi-surface SL was previously encountered in an organic triangular-lattice antiferromagnet, suggesting a common destabilization mechanism that most likely arises from spinon pairing. A salient property of this instability is that an infinitesimal field suffices to induce it, as predicted theoretically for some other types of gapless SLs.
量子 Kagome 反铁磁体羟铜锌矿（ZnCu₃(OH)₆SO₄）是二维或三维中仅有的少数已知自旋液体（SL）实例之一，其基态被描述为具有自旋子费米面的无隙 SL。我们在低至毫开尔文温度的宽磁场范围内利用核磁共振表明，在施加磁场时，这种神秘状态对于具有完全或部分能隙的 SL 本质上是不稳定的。之前在一种有机三角晶格反铁磁体中也遇到过无隙费米面 SL 的类似不稳定性，这表明一种很可能源于自旋子配对的共同失稳机制。这种不稳定性的一个显著特性是，如理论上对其他一些类型的无隙 SL 所预测的那样，极小的磁场就足以诱发它。
Zotero 插件