After describing our quantum noise model, we rst develop a new motion-adaptive temporal lter based on a recursive structure. Compared to other motion-adaptive lters, our lter is much less prone to generate artefacts known as noise tails. We then describe spatial ltering techniques derived from the concept of spectral amplitude estimation. These lters work in the spectral domain, and can conveni...

The quantum noise of the light field is a fundamental noise source in interferometric gravitational wave detectors. Injected squeezed light is capable of reducing the quantum noise contribution to the detector noise floor to values that surpass the so-called Standard-Quantum-Limit (SQL). In particular, squeezed light is useful for the detection of gravitational waves at high frequencies where i...

We formulate a scheme for fault-tolerant quantum computation that works effectively against highly biased noise, where dephasing is far stronger than all other types of noise. In our scheme, the fundamental operations performed by the quantum computer are single-qubit preparations, single-qubit measurements, and conditionalphase CPHASE gates, where the noise in the CPHASE gates is biased. We sh...