The field of quantum information evolved from exploration of IBM scientist Rolf Landauer’s dictum: “information is physical”. The laws of physics, in other words, stipulate the behaviour of all carriers of information and thereby determine the rules of information processing too. Researchers at CQT explore, theoretically and experimentally, the issues that arise when the carriers of information are quantum.
On the theory side, we first and foremost investigate entanglement, a form of quantum correlation absent in classical systems. An important problem is understanding how entanglement behaves in many-body systems, which can teach us about possible limitations on the size of quantum information processing devices. More profoundly, we can ask what implications the existence of macroscopic entanglement has for our understanding of the world around us. Is entanglement guaranteed to vanish under some external conditions, leading to the usual world of classical physics? Or is entanglement ubiquitous in Nature? CQT scientists are exploring theoretical proposals for experimental tests of various quantum-to-classical transitions. Last but not least, an exciting possibility is emerging that biological systems engage in quantum information processing. Would this allow us to reverse-engineer Nature in order to make the first quantum computer?
Flipping Landauer’s dictum around (“physics is informational”) leads to a host of other exciting research directions. Here at CQT we would like to know if quantum physics can be derived from some kind of information theoretic principles. Furthermore, if such principles exist, can they tell us not only about quantum physics, but also about the way quantum physics might be modified in the future to yield an even more precise theory? The prospect of a post-quantum theory is always exciting to physicists, but there are practical hopes too: such a theory may allow for even more efficient information processing and could therefore benefit us greatly. We already have glimpses of post-quantum secret communication; how far into other technology does this stretch?