美科学家研究超导场效应晶体管取得重大进展

对超导性的电阻提出合理诠释，促使美国能源部（DOE）下属机构布鲁克海文（Brookhaven）国家实验室制造出了完美的原子级超薄膜，精确地表现出从绝缘体转变为超导体的特征。

研究人员使用普通的绝缘铜氧化物（铜酸盐）形成一个类似场效应晶体管（FET）的沟道，同时利用分子束外延（MBE）来长出完美的原子级超导薄膜。到目前为止，研究人员已经证明，通过外加电场可以调节材料的超导开启温度多达30K，比以前报道的结果提高了10倍以上，该项目主任研究员Ivan Bozovic表示。

Bozovic表示，他们毫米规模的材料也使之成为宏观样品中表现量子力学特性的几个例子之一。他的研究小组还发现证据表明，库珀电子对对超导性——实际上是转变为超导体之前的过渡阶段——是很必要的，而且他们的薄膜显示了精确的电阻值，该过渡到超导体时的电阻值已由量子力学预言，也就是6.45KΩ（h/2e²）。

Bozovic说，随着我们不断探索这些奥秘，我们也在努力使超高速节能超导电子学成为可能。

图：布鲁克海文国家实验室的物理学家Ivan Bozovic想了解为什么薄膜绝缘体转变到超导状态

超导场效应晶体管将会更快，功耗更低，并且可以比当前传统的晶体管封装得更密集，以及具有新的工作模式诸如利用外加电场调节超导性的能力。

Bozovic表示，这只是一个开始。

编译：Aileen Zhu

点击参考原文：Lab aims for superconducting FET

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Lab aims for superconducting FET

R. Colin Johnson

The resistance of superconductivity to rational explanation has prompted the U.S. Department of Energy’s (DoE) Brookhaven National Laboratory to fabricate atomically perfect ultra-thin-films capable of accurately characterize the transition from an insulator to superconductor.

A normally insulating copper-oxide material (cuprate) was configured like the channel of a field-effect transistor (FET), using molecular beam epitaxy to create an atomically perfect superconducting film. So far the researchers have demonstrated that an external electric field can tune the temperature at which the material superconducts by as much 30 degrees Kelvin, a tenfold increase over previous reported results, according to principle researcher on the project, Ivan Bozovic.

According to Bozovic, the millimeter scale of their material also makes it one of the few examples of quantum-mechanical behavior at the macroscopic sample. His team has also found evidence that the Cooper-pairing of electrons, necessary for superconductivity, actually precedes the transition, and that their films exhibit the exact resistance predicted by quantum mechanics when they transition to superconductivity, namely 6.45 kilo-ohms (Planck's quantum constant divided by twice the electron charge squared).

As we continue to explore these mysteries, we are also striving to make ultrafast and power-saving superconducting electronics a reality, said Bozovic.

Brookhaven physicist Ivan Bozovic wants to understand why a thin-film insulator transitions to the superconducting state.Source Brookhaven National Labs.

Superconducting FETs would be faster, lower power and could be packed more densely than conventional transistors today, plus could have novel new operation modes such as the ability to modulate superconductivity with an external electric field.

This is just the beginning, Bozovic said.