论文标题
YBA $ _2 $ CU $ _3 $ o $ _7 $ _7 $/srtio $ _3 $超级奏效的nanosquids与Bicrystal晶粒边界Josephson交界处
NanoSQUIDs from YBa$_2$Cu$_3$O$_7$/SrTiO$_3$ superlattices with bicrystal grain boundary Josephson junctions
论文作者
论文摘要
We report on the fabrication and characterization of nanopatterned dc SQUIDs with grain boundary Josephson junctions based on heteroepitaxially grown YBa$_2$Cu$_3$O$_7$ (YBCO)/ SiTrO$_3$ (STO) superlattices on STO bicrystal substrates.纳米图案由GA聚焦离子梁铣削执行。超晶格纳米晶的电运输特性和热白色通量噪声可与Sto Bicrystals上的单层YBCO设备相媲美。但是，我们发现超级晶格纳米喹词的低频噪声较小，其较小的噪声较小，并且具有根平方的光谱密度$s_φ^{1/2} \ sim 5-6 \，μφ_0/\μφ_0/\ sqrt sqrt {\ rm hz} $ hz $ hz（$ hz（$ hz）（$ hz）（$ hz（$ rm hz）（$ yum）$ qunignium是$ qumention the $ q ym $ s ym $ s y rem $ s them opds them $ qumφ我们将这种改进归因于在YBCO纳米Quds中形成Josephson连接的晶界的改进微观结构。
We report on the fabrication and characterization of nanopatterned dc SQUIDs with grain boundary Josephson junctions based on heteroepitaxially grown YBa$_2$Cu$_3$O$_7$ (YBCO)/ SiTrO$_3$ (STO) superlattices on STO bicrystal substrates. Nanopatterning is performed by Ga focused-ion-beam milling. The electric transport properties and thermal white flux noise of superlattice nanoSQUIDs are comparable to single layer YBCO devices on STO bicrystals. However, we find that the superlattice nanoSQUIDs have more than an order of magnitude smaller low-frequency excess flux noise, with root-mean-square spectral density $S_Φ^{1/2}\sim 5-6\,μΦ_0/\sqrt{\rm Hz}$ at 1 Hz ($Φ_0$ is the magnetic flux quantum). We attribute this improvement to an improved microstructure at the grain boundaries forming the Josephson junctions in our YBCO nanoSQUDs.
