Superconducting semiconductor hybrids for future qubit

Nyomtatóbarát változatNyomtatóbarát változat
Doctoral school: 
Fizikai Tudományok Doktori Iskola
Szabolcs Csonka
Department of Physics
Job title: 
associate professor
Academic degree: 

Superconducting qubits presently provide the most advanced platform for quantum computation. Still errors coming from local noise sources place serious limitation to use these quantum hardware for useful computational tasks. One direction to overcome this limitation is to massively scale up the number of physical qubits which is the mainstream of the field at the moment. Other alternative solution is to improve the physical qubit, which would allow to carry out calculations with significantly lower number of qubits.

Recent theoretical proposals suggest promising directions how to improve a transmon qubit by replacing the Josephson junction with topological protected units. The goal of the present project is to develop a so-called Kitaev transmon, which contains a chain of quantum dots coupled by superconducting spacers at the place of the Josephson-junction. To this end, quantum dot - superconducting arrays planned to be developed either on InAs nanowire platform or InAs 2DEGs. Thanks to leading growers of the field, we have access to high quality MBE grown semiconductor nanostructures with epitaxial superconducting capping layer. These wire or 2DEG structures allow to realize gateable confinement in the semiconductor segments to form dots, while the superconductor layer could serve as a spacer and connection to the other part of the transmon circuit.

The project contains the development of novel quantum circuits based on e-beam lithography technique, DC transport characterization of the structures, designing appropriate microwave surrounding of the qubit and carry out high frequency measurements of the devices.

The work is done in close collaboration with in-house theoreticians and several European universities in the framework of EU networks.


Knowledge of quantum mechanics and solid state physics, motivation for experimental work, English knowledge, basic programming and measurement automation experience. Good skills for theoretical modelling.
Project type: 
PhD project for standard admission