论文标题
在压力下，较重的弗里米式超导体UTE2中的上临界场各向异性
Anisotropy of the Upper Critical Field in the Heavy-Fermion Superconductor UTe2 under Pressure
论文作者
论文摘要
我们研究了超导的上临界场的各向异性$ h _ {\ rm c2} $在静水压力下通过磁层测量测量在静水压力下的重型纤维超导体UTE $ _2 $。与以前的实验一致，我们确认超导性在临界压力附近消失$ p _ {\ rm c} \大约1.5 $ 〜GPA，并且出现了磁性有序状态。 $ h \ parallel A $在低温下的不寻常$ h _ {\ rm c2}（t）$表明，在压力下出现的多个超导阶段的$ h _ {\ rm c2} $完全不同。对于沿硬磁化$ b $ axis $ h _ {\ rm c2}（0）$粘贴到元磁过渡$ h _ {\ rm m} $的字段，该$被压制在$ p _ {\ rm c} $上。压力下的$ h _ {\ rm m} $的抑制遵循温度的降低$t_χ^{\ rm max} $，最大程度地沿着$ b $。由于$ t _ {\ rm sc} $的增加，在压力下迅速抑制了$ h _ {\ rm c2} $在$ h \ parallel b $以上的环境压力下的强大加固，并且$ h _ {\ rm mm} $的下降。 $ h _ {\ rm c2}（0）$的各向异性层次结构的变化在接近$ p _ {\ rm c} $时指出，$ c $ axis成为硬磁化轴。
We studied the anisotropy of the superconducting upper critical field $H_{\rm c2}$ in the heavy-fermion superconductor UTe$_2$ under hydrostatic pressure by magnetoresistivity measurements. In agreement with previous experiments we confirm that superconductivity disappears near a critical pressure $p_{\rm c} \approx 1.5$~GPa, and a magnetically ordered state appears. The unusual $H_{\rm c2}(T)$ at low temperatures for $H \parallel a$ suggests that the multiple superconducting phases which appear under pressure have quite different $H_{\rm c2}$. For a field applied along the hard magnetization $b$ axis $H_{\rm c2} (0)$ is glued to the metamagnetic transition $H_{\rm m}$ which is suppressed near $p_{\rm c}$. The suppression of $H_{\rm m}$ with pressure follows the decrease of temperature $T_χ^{\rm max}$, at the maximum in the susceptibility along $b$. The strong reinforcement of $H_{\rm c2}$ at ambient pressure for $H \parallel b$ above 16~T is rapidly suppressed under pressure due to the increase of $T_{\rm sc}$ and the decrease of $H_{\rm m}$. The change in the hierarchy of the anisotropy of $H_{\rm c2}(0)$ on approaching $p_{\rm c}$ points out that the $c$ axis becomes the hard magnetization axis.
