AI 中文总结
研究在三角晶格反铁磁体TlYbS₂中发现了由分数化激发主导、超出金兹堡-朗道范式的连续禁闭-解禁闭相变，其临界行为与传统磁量子临界性不同。
AI 中文摘要
在量子磁学领域，存在一种长期被追寻的现象：承载不同激发（玻色型磁振子与费米型自旋子）的相之间的连续相变，这与量子色动力学中的禁闭-解禁闭相变类似。我们在三角晶格反铁磁体TlYbS₂中报道了此类相变的证据：在TN≈0.53K以下会形成反铁磁有序；当沿c轴施加磁场时，该有序会被抑制，当μ0Hc≈3T时，系统会进入带有自旋子费米面的无隙量子自旋液体相，热导率中存在有限的剩余线性项、类泡利磁化率以及与温度无关的NMR奈特位移可为此提供佐证。从Hc以上趋近该临界值时，巡游激发的散射率会显著增强，但其态密度未出现临界增强，这与传统磁量子临界性的特征不符。这些结果表明，该连续禁闭-解禁闭相变由分数化激发主导，超出了金兹堡-朗道范式的描述范畴。
英文摘要
A continuous transition between phases hosting distinct excitations---bosonic magnons versus fermionic spinons---is a long-sought phenomenon in quantum magnetism, analogous to the confinement--deconfinement transition in quantum chromodynamics. We report evidence for such a transition in the triangular-lattice antiferromagnet TlYbS$_2$. Antiferromagnetic order develops below $T_\mathrm{N} \approx 0.53\,\mathrm{K}$. A $c$-axis field suppresses this order, driving the system into a gapless quantum spin liquid with a spinon Fermi surface above $μ_0 H_\mathrm{c} \approx 3\,\mathrm{T}$, evidenced by a finite residual linear term in thermal conductivity, a Pauli-like susceptibility, and a temperature-independent NMR Knight shift. Approaching $H_\mathrm{c}$ from above, the scattering rate of itinerant excitations is strongly enhanced while their density of states shows no critical enhancement, atypical of conventional magnetic quantum criticality. These results point to a continuous confinement--deconfinement transition governed by fractionalized excitations beyond the Ginzburg--Landau paradigm.
Comments10 pages, 4 figues
