Coulomb blockade and Coulomb staircases in CoBi nanoislands on SrTiO3(001)

Yumin Xia; Desheng Cai; Jiaqing Gao; Pengju Li; Kun Xie; Yuzhou Liu; Yitong Gu; Gan Yu; Ping Cui; Shengyong Qin

doi:10.1088/1361-6528/ad1943

Coulomb blockade and Coulomb staircases in CoBi nanoislands on SrTiO₃(001)

Nanotechnology. 2024 Apr 30;35(29). doi: 10.1088/1361-6528/ad1943.

Authors

Yumin Xia^{1

2}, Desheng Cai^{1

2}, Jiaqing Gao¹, Pengju Li^{1

2}, Kun Xie^{1

2}, Yuzhou Liu^{1

2}, Yitong Gu^{1

2}, Gan Yu^{1

2}, Ping Cui^{1

3}, Shengyong Qin^{1

2

3}

Affiliations

¹ International Center for Quantum Design of Functional Materials (ICQD), University of Science and Technology of China, Hefei, 230026, People's Republic of China.
² CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
³ Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, People's Republic of China.

PMID: 38154130
DOI: 10.1088/1361-6528/ad1943

Abstract

We successfully fabricated two-dimensional metallic CoBi nanoislands on SrTiO₃(001) substrate by molecular beam epitaxy, and systematically investigated their electronic structures by scanning tunneling microscopy and spectroscopyin situat 4.2 K. Coulomb blockade and Coulomb staircases with discrete and well-separated levels are observed for the individual nanoisland, which is attributed to single-electron tunneling via two tunnel junction barriers. They are in excellent agreement with the simulations based on orthodox theory. Furthermore, we demonstrated that the Coulomb blockade becomes weaker with increasing temperature and almost disappears at ∼22 K in our variable temperature experiment, and its full-width at half-maximum of dI/dVpeaks with temperature is ∼6 mV. Our results provide a new platform for designing single-electron transistors that have potential applications in future microelectronics.

Keywords: CoBi/SrTiO3; Coulomb blockade; Coulomb staircases; single electron tunneling.