论文标题
$ ba_ {1-x} na_ {x} fe_ {2} as_ {2} $的muon自旋旋转和红外光谱研究
Muon spin rotation and infrared spectroscopy study of $Ba_{1-x}Na_{x}Fe_{2}As_{2}$
论文作者
论文摘要
一系列不足的$ ba_ {1-x} na_ {x} fe_ {2} as_ {2} $（bnfa）单晶体的磁性和超导能特性，该晶体具有$ 0.19 \ leq x \ leq x \ leq 0.34 $的调查，并已与互补的muon-spin-spin-spin-spin-rotation（$ s-spin-spin-retation（$ s）进行了调查（重点一直放在被压倒式状态的不同抗磁性状态以及他们具有超导性的竞争中，尤其是对于具有四方晶体结构和所谓的Double-$ Q $磁性序列的抗磁性状态。除了在$ x = 0.24 $和0.26 $的空间不均匀旋转式密度波（I-SCDW）订单外，除了共线状态外，我们还在BNFA中鉴定出来，我们还获得了具有“ HEDGEHOG”的正磁状态的证据，具有“ HEDGEHOG” -HEDGEHOG SPITEX SPILEX CYRTEX CRYTREX CRYTER（SVC）的结构。尽管在前I-SCDW状态下，红外光谱没有显示出超导反应的迹象，以至于最低的测得的温度约为10K，在SVC状态下，有强大的超导反应反应，类似于最佳掺杂时类似的响应。在超导状态下，磁性顺序强烈抑制，在$ x = 0.34 $时，甚至在$ t << t_c $的情况下，甚至部分重新进入顺磁性状态。
The magnetic and superconducting properties of a series of underdoped $Ba_{1-x}Na_{x}Fe_{2}As_{2}$ (BNFA) single crystals with $0.19 \leq x\leq 0.34$ has been investigated with the complementary muon-spin-rotation ($μ$SR) and infrared spectroscopy techniques. The focus has been on the different antiferromagnetic states in the underdoped regime and their competition with superconductivity, especially for the ones with a tetragonal crystal structure and a so-called double-$Q$ magnetic order. Besides the collinear state with a spatially inhomogeneous spin-charge-density wave (i-SCDW) order at $x=0.24$ and $0.26$, that was previously identified in BNFA, we obtained evidence for an orthomagnetic state with a "hedgehog"-type spin vortex crystal (SVC) structure at $x=0.32$ and $0.34$. Whereas in the former i-SCDW state the infrared spectra show no sign of a superconducting response down to the lowest measured temperature of about 10K, in the SVC state there is a strong superconducting response similar to the one at optimum doping. The magnetic order is strongly suppressed here in the superconducting state and at $x=0.34$ there is even a partial re-entrance into a paramagnetic state at $T<<T_c$.
