Dang Phillip, Khalsa Guru, Chang Celesta S, Katzer D Scott, Nepal Neeraj, Downey Brian P, Wheeler Virginia D, Suslov Alexey, Xie Andy, Beam Edward, Cao Yu, Lee Cathy, Muller David A, Xing Huili Grace, Meyer David J, Jena Debdeep
School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA.
Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA.
Sci Adv. 2021 Feb 19;7(8). doi: 10.1126/sciadv.abf1388. Print 2021 Feb.
Creating seamless heterostructures that exhibit the quantum Hall effect and superconductivity is highly desirable for future electronics based on topological quantum computing. However, the two topologically robust electronic phases are typically incompatible owing to conflicting magnetic field requirements. Combined advances in the epitaxial growth of a nitride superconductor with a high critical temperature and a subsequent nitride semiconductor heterostructure of metal polarity enable the observation of clean integer quantum Hall effect in the polarization-induced two-dimensional (2D) electron gas of the high-electron mobility transistor. Through individual magnetotransport measurements of the spatially separated GaN 2D electron gas and superconducting NbN layers, we find a small window of magnetic fields and temperatures in which the epitaxial layers retain their respective quantum Hall and superconducting properties. Its analysis indicates that in epitaxial nitride superconductor/semiconductor heterostructures, this window can be significantly expanded, creating an industrially viable platform for robust quantum devices that exploit topologically protected transport.
对于基于拓扑量子计算的未来电子学而言，创建展现量子霍尔效应和超导性的无缝异质结构是非常可取的。然而，由于相互冲突的磁场要求，这两个拓扑稳健的电子相通常是不相容的。具有高临界温度的氮化物超导体的外延生长以及随后具有金属极性的氮化物半导体异质结构的联合进展，使得在高电子迁移率晶体管的极化诱导二维（2D）电子气中能够观察到清晰的整数量子霍尔效应。通过对空间分离的GaN二维电子气和超导NbN层进行单独的磁输运测量，我们发现了一个小的磁场和温度窗口，在外延层在其中保持其各自的量子霍尔和超导特性。其分析表明，在外延氮化物超导体/半导体异质结构中，这个窗口可以显著扩大，从而为利用拓扑保护输运的稳健量子器件创建一个具有工业可行性的平台。
