Compound Semiconductor Seminar - Professor Greg Mazur

Compound Semiconductors: Electronics, Optoelectronics & Quantum Seminar

Wednesday, May 6, 2026, 12:00PM

Attend in person at the Engineering Sciences Building 1001

Dr. Greg Mazur, Asst. Professor, Materials Department
Artificial Kitaev chain in InSb/Al semiconductor/superconductor hybrids

Hybrid semiconductor–superconductor systems have attracted growing interest as a platform for engineering emergent states of matter and, in particular, for realizing fault-tolerant topological quantum computation [1,2]. Narrow-gap III–V semiconductors such as InSb and InAs are prime candidates for this purpose: their low effective mass, large Landé g-factor, and strong spin–orbit coupling are precisely the ingredients required by theoretical proposals for inducing topological superconductivity in a conventional s-wave superconductor proximitizing a one-dimensional semiconductor channel [3,4]. In this talk I will discuss how coupling InSb nanowires to superconducting aluminum [5] can be used to build devices that implement the Kitaev chain - a tight-binding model of a 1D p-wave superconductor whose end states are unpaired Majorana zero modes [5]. I will focus on the "minimal" realization of this model in arrays of gate-defined quantum dots coupled through superconducting segments [6,7,8]. I will discuss how to fabricate this devices, the principle of the Kitaev model and how to use this platform for quantum technology purposes.

References:

 [1] A. Y. Kitaev, Phys.-Usp. 44, 131 (2001).

[2] C. Nayak et al., Rev. Mod. Phys. 80, 1083 (2008).

[3] R. M. Lutchyn, J. D. Sau & S. Das Sarma, Phys. Rev. Lett. 105, 077001 (2010).

[4] Y. Oreg, G. Refael & F. von Oppen, Phys. Rev. Lett. 105, 177002 (2010).

[5] A. Y. Kitaev, Phys.-Usp. 44, 131 (2001).

[6] M. Leijnse & K. Flensberg, Phys. Rev. B 86, 134528 (2012).

[7] T. Dvir et al., Nature 614, 445 (2023).

[8] A. Bordin et al., Nat. Nanotechnol. (2025) — "Enhanced Majorana stability in a three-site Kitaev chain."

Greg Mazur got his PhD in semiconductor physics at the Polish Academy of Sciences. He then moved to QuTech, TU Delft in the Netherlands as a post-doc. After that, he worked at Microsoft Quantum as a Senior Measurement Engineer. Before moving to UCSB, he held a lectureship in quantum technologies at the University of Oxford. His group develops semiconductor/superconductor hybrid devices for quantum technologies based on two-dimensional electron gases in InAs/InSb and strained germanium quantum wells.

HOST: Assoc. Professor Elaheh Ahmadi, Electrical & Computer Engineering Department