A child on a swing can keep the swing in motion by repeatedly standing up and squatting down. This movement changes the frequency of the swings and amplifies them. This simple concept—known as parametric amplification—finds use also in modern quantum physics.
Entanglement is a peculiar feature of quantum systems that makes them behave as if they were sitting directly next to each other even if they are kilometres away. Such behaviour does not occur in classical physics. Classical particles can affect each other through fields -- such as the gravitational or electromagnetic field -- but these fields propagate with… Continue reading Connecting superconducting quantum computers with light
claimtoken-552906769c445 I already talked about using measurements and feedback in quantum physics and how these tools can be used to prepare interesting quantum states. But it is not an easy task -- experimental realisations require ultrafast electronics to apply feedback in real time. And theoretical analyses? Those are not easy either. Take a simple example -- an… Continue reading Simplifying quantum systems
Do you remember your first computer? And your first internet connection? Sure, they were not as powerful as today's technology but it was something completely new and opened many possibilities. A quantum computer, ideally connected to quantum internet, must then be even more remarkable. Although it is true that algorithms for quantum computers focus on… Continue reading Building the quantum internet
The basic picture of an optomechanical system, that even many scientists keep in mind, is that of a cavity with one movable mirror. But that is not the only way to achieve coupling between light and mechanical vibrations. Every time light is strong enough (and the mechanical oscillator light enough), the light can be used to… Continue reading Wi-Fi for a quantum computer