It is impossible to picture modern life without thinking of the vast amount of microelectronic applications that surround us. However, such development has only become possible with the invention of the transistor in the 1950’s. This – back at that time – few centimeters large device, led to a technological revolution. Today the size of the transistors has been shrunk to 7nm where quantum physics comes into play. Researchers are now developing new concepts and techniques using quantum mechanics to allow information processing to operate on completely different principles and to create a quantum computer.
In this line, Loss and DiVincenzo suggested in 1998 the use of electron spins confined in lithographically defined quantum dots as elementary qubits to realize a quantum computer. In the past few years, holes in Germanium have emerged as a very promising platform for the realization of these spin qubits, due to their small effective mass and large spin orbit coupling and absence of the valley problem faced by non-confined electron spins. In addition, in the quantum information community there has been recently a huge wave of excitement about the prospect of using protected qubits for quantum computation. Such protection can be realized on the hardware-level by using topological qubits or cleverly designed electrical circuits.
In the nanoelectronics group, we study spin qubits in two-dimensional Germanium heterostructures and in parallel, we aim to understand whether protected qubits can be realized in hybrid semiconductor-superconductor systems. While our research is focused on the realization of different types of qubits, the group is very much interested in studying new fundamental physics emerging in semiconductor nanodevices.