Do you have absolutely no knowledge about quantum physics? Do you want to get at least a basic understanding about what it is, why it is important, or how it can be relevant to everyday life? I just added a new page that tries to explain some of these basic questions in (I hope) an… Continue reading New page on the basics of quantum physics
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
There can never be a truly empty space. That was the opinion of many scholars from the times of ancient Greece up to the beginning of the twentieth century. When the idea of aether as a medium in which light can travel has been refuted, the existence of vacuum became widely accepted. But then the… Continue reading Is nature scared of emptiness?
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
When students encounter quantum physics for the first time, it is as simple as it gets -- there are no unwanted interactions, no noise, particles do not get lost. In the real world, nothing is so easy, though. Take a single atom placed in an optical cavity, for instance. (The cavity helps to enhance the… Continue reading How to close an open system
Using light, we can achieve more than simply see the world around us. Spectroscopy can be used to find chemical composition of a sample, frequency of light interacting with atoms can be used to measure time. We can even move objects by shining light at them. Such manipulations are far from tractor beams of science fiction, but optical tweezers are commonly used to manipulate small objects in many labs around the world. And there are other ways how to control matter using light.