In July-August there have been two important events in our group. Andres Rosario has easily passed his confirmation. Anatoly Kulikov who visited us previously in December 2015- February 2016 has been awarded UQ International Scholarship and started his PhD in our lab. Congratulations to Andres and welcome to Anatoly!
Qubits placed in a open waveguide may play a role of mirror for microwave radiation. These are not standard mirrors though as the reflectivity is frequency and power dependent. If there are more than one qubit in a waveguide these properties may give rise interesting effects (for the first experiments with two qubit in a waveguide see this paper). But else they can be good for? Following the idea of Arjan van Loo we can use qubits for drawing pictures!
We have uploaded a theoretical proposal proposal on cooling the large quartz reosnator by coupling it to a superconducting qubit. Unlike nanomechanical oscillators Bulk Acoustic Wave (BAW) oscillators offer exceptional mechanical properties such as extremely high quality factors. Yet them coupling to qubits it is not easy due to unavoidable large stray capacitance. Our paper investigates a possible solution to this problem which should allow to cool BAW oscillator to its ground state.
Three-dimensional (3D) superconducting microwave cavities have exceptional quality factors but do not allow magnetic field to penetrate inside them. It is also hard to thermalize them to the cold stage of a dillution refrigirator. A copper cavity can be thermalized and allows for magnetic control but its quality factor is limited. In our new work we tried to reach a compomise between quality factor and magnetic tunability by creating "hybrid cavity" which consists of both superconductor and normal metal. Find out what were the outcomes in our new paper.