Masters defense: Torbjørn Raasø Rasmussen

Autonomous tuning of gate-controlled quantum dots and Hall bars

As the scientific community moves towards realising quantum computers in semiconductor devices, these gate-controlled nanoscale devices themselves are becoming progressively more complex. The need for automated solutions for tuning and characterisation has become apparent, as the parameter space of very complex devices are quickly becoming too large to manually investigate. In this project we have focused on two different platforms for the investigation of automated exploration of quantum devices. For spin-qubits in gate-defined quantum dots we have developed an algorithm that automatically estimates the charge state boundaries in two- and three- dimensional gate-voltage space. For optimisation of quantum Hall physics within the constriction of a quantum point contact, we have implemented an algorithm that modulates the gate voltages applied to an array of pixel gates located above the constriction of the quantum point contact. Both algorithms have been tested on real devices in dilution refrigerators at subkelvin temperatures.  


Meeting ID: 654 1589 4449
Passcode: 896100