论文标题
现场引起的量子关键点在新的巡回抗Fiferromagnet ti $ _3 $ cu $ _4 $中
Field-induced quantum critical point in the new itinerant antiferromagnet Ti$_3$Cu$_4$
论文作者
论文摘要
物质的新阶段出现在磁不稳定性的边缘。在诸如重型费米斯之类的当地瞬间系统中，磁力可能会因压力，化学掺杂而不稳定，并且很少通过磁场向量子关键点（QCP）处的零温转换。 QCP的实例甚至更为罕见，这是由巡回矩系统中的压力或掺杂引起的，没有类似场诱导的\ textIt {t} = 0过渡的已知示例。在这里，我们报告了没有磁成分的新的巡回抗铁磁铁，在Ti $ _3 $ _3 $ _3 $ cu $ _4 $的单晶中，带有$ t_n $ = 11.3 K.频带结构的计算指向圆锥形的，旋转的，旋转密度的基地状态状态，是方形的旋转密度底层状态，是方形结构性的结构净结构型，在Ti $ $ _3 $ _3 $ cood $ _3 $ __4。一个小的磁场，$ h_c $ = 4.87 t，通过连续的二阶过渡抑制了远距离顺序，从而导致了场诱导的QCP。磁性grüneisen比率为$ h \ rightarrow h_c $和$ t \ rightarrow0 $，符号更改为$ h_c $，$ t^{ - 1} $缩放在$ h〜 = 〜h_c $上，从$ h〜 = 〜h_c $中缩放，提供了$ h \ h_c $的量子性测量值的证据。如电阻率的功率定律行为所揭示的那样，观察到接近QCP的非富富液体（NFL）到费米液体（FL）跨界。
New phases of matter emerge at the edge of magnetic instabilities. In local moment systems, such as heavy fermions, the magnetism can be destabilized by pressure, chemical doping, and, rarely, by magnetic field, towards a zero-temperature transition at a quantum critical point (QCP). Even more rare are instances of QCPs induced by pressure or doping in itinerant moment systems, with no known examples of analogous field-induced \textit{T} = 0 transitions. Here we report the discovery of a new itinerant antiferromagnet with no magnetic constituents, in single crystals of Ti$_3$Cu$_4$ with $T_N$ = 11.3 K. Band structure calculations point to an orbital-selective, spin density wave ground state, a consequence of the square net structural motif in Ti$_3$Cu$_4$. A small magnetic field, $H_C$ = 4.87 T, suppresses the long-range order via a continuous second-order transition, resulting in a field-induced QCP. The magnetic Grüneisen ratio diverges as $H \rightarrow H_C$ and $T\rightarrow0$, with a sign change at $H_C$ and $T^{-1}$ scaling at $H~=~H_C$, providing evidence from thermodynamic measurements for quantum criticality for $H \parallel c$. Non-Fermi liquid (NFL) to Fermi liquid (FL) crossover is observed close to the QCP, as revealed by the power law behavior of the electrical resistivity.
