Institute for Theoretical Solid State Physics, IFW Dresden, 01171 Dresden, Germany.
Nat Commun. 2013;4:2287. doi: 10.1038/ncomms3287.
Quantum spin-1/2 kagome Heisenberg antiferromagnet is the representative frustrated system possibly hosting a spin liquid. Clarifying the nature of this elusive topological phase is a key challenge in condensed matter; however, even identifying it still remains unsettled. Here we apply a magnetic field and discover a series of spin-gapped phases appearing at five different fractions of magnetization by means of a grand canonical density matrix renormalization group, an unbiased state-of-the-art numerical technique. The magnetic field dopes magnons and first gives rise to a possible Z₃ spin liquid plateau at 1/9 magnetization. Higher field induces a self-organized super-lattice unit, a six-membered ring of quantum spins, resembling an atomic orbital structure. Putting magnons into this unit one by one yields three quantum solid plateaus. We thus find that the magnetic field could control the transition between various emergent phases by continuously releasing the frustration.
量子自旋-1/2 kagome 海森堡反铁磁体是可能存在自旋液体的典型受挫系统。阐明这个难以捉摸的拓扑相的本质是凝聚态物质中的一个关键挑战；然而，即使确定它仍然存在争议。在这里，我们通过大正则密度矩阵重整化群这一公正的最先进的数值技术，施加磁场并发现了在五个不同的磁化分数处出现的一系列自旋隙相。磁场掺杂磁振子，并首先在 1/9 的磁化率处产生可能的 Z₃ 自旋液体平台。更高的磁场诱导自组织超晶格单元，即量子自旋的六元环，类似于原子轨道结构。将磁振子一个一个地放入这个单元中，得到三个量子固体平台。因此，我们发现磁场可以通过不断释放受挫来控制各种涌现相之间的转变。
