Systems and tools

Circuit quantum electrodynamics

Superconductors enable electrical current to pass through without any resistance. Electrical circuits for information processing in these materials make it possible to preserve the quantum nature of the current and are thus suitable for encoding and processing quantum information. I am particularly interested in understanding how such quantum computing chips can be connected to light and form quantum communication networks.

Cavity optomechanics

Interaction between light and mechanical oscillators—small drums or tiny strings—offers a powerful tool to control and read out mechanical motion. Measuring the motion can give us useful information about external influences acting on the oscillator, such as electric or magnetic fields and even passing gravitational waves. We can also use optomechanics for testing the predictions of quantum physics at large scales or for building networks of quantum computers. Read more

Quantum measurement and feedback

Quantum systems interact with their environment which usually leads to them behaving classically. Nevertheless, when we observe the environment, we can learn about our quantum system’s behaviour and use this information to preserve the system’s quantum nature or to perform useful operations.

Gaussian states and operations

Mathematical description of quantum systems poses many challenges; the size of the mathematical objects describing the system (the wavefunction or density operator) grows exponentially with the size of the system. In some cases, however, the description can be simplified owing to the internal structure of the system and its dynamics. One such class of systems is characterized by having Gaussian phase-space distribution and can cover, among other things, a broad range of operations performed on light or mechanical oscillators.