Fundamental questions of physics are still unanswered. It remains unclear what a large part of the universe is made of, as the mysterious dark matter has not yet been detected. According to the laws of nature, however, it should exist in order to keep the universe together. Although the theories of gravity and quantum mechanics are coherent and well-established, they have not yet been able to be unified in a single formula. More than 60 physicists from Leibniz Universität Hannover (LUH) and the Physikalisch Technische Bundesanstalt (PTB) in Braunschweig are cooperating in the DQ-mat Collaborative Research Centre to contribute to answering these and other fundamental questions. They unite complex quantum physics and high-precision measurement methods to develop new types of quantum sensors for extremely accurate measuring devices. Since the consortium was launched in 2016, it has developed into the leading German centre for quantum metrology and is also a global player in this field. The German Research Foundation (DFG) has now approved an extension for a further four years and is funding the Collaborative Research Centre with around 10 million euros.
"We are absolutely delighted about this confirmation of our work, because we are at a very exciting point," says Piet Schmidt, physics professor at LUH and PTB and spokesperson for the Collaborative Research Centre. "We know that something is missing in the big physical picture and we can really help to close these gaps with our experiments and the associated theoretical foundations in the Collaborative Research Centre." DQ-mat brings together experts from the fields of metrology and quantum optics as well as many-body physics and quantum information, creating a unique combination.
"I am very happy about the extension of the Collaborative Research Centre DQ-mat and thank the researchers involved for their great and lasting commitment," says Prof. Dr Volker Epping, President of Leibniz Universität Hannover. "This success contributes to strengthening the research focus on quantum optics and gravitational physics at our university, it deepens the good and established relationships between the partners Leibniz Universität, PTB and DLR-SI and it can support the proposal for the continuation of our Cluster of Excellence QuantumFrontiers."
Lower Saxony's Science Minister Falko Mohrs adds: "The excellent news that the Collaborative Research Centre "Designed Quantum States of Matter" was successful for the second time and has received renewed funding from the DFG shows the strength of this project and the researchers and institutions involved. My heartfelt congratulations go to the team and their pioneering developments in this future technology! This success once again emphasises the importance of Lower Saxony as a location for the key technology of quantum research."
The measuring instruments used by DQ-mat researchers are already among the most accurate in the world. But in order to get closer to solving the big questions of physics, they need even more precise devices. In the Collaborative Research Centre, they are therefore developing the next generation of quantum sensors for even more sensitive, faster and highresolution measuring instruments such as atomic clocks or atomic interferometers. In combination with quantum technology methods, the scientists want to unlock the full potential of quantum mechanics in precision measurements. Their aim is to achieve measurements that are up to a hundred times more accurate or faster.
The researchers have already achieved important successes in the second funding period, which is now coming to an end. This spring, for example, they were able to excite the atomic nucleus of the element thorium-229 to make a quantum leap. What sounds unspectacular had not been achieved by researchers for decades and is a scientific breakthrough. It opens the door to new types of atomic clocks that could be significantly more accurate than today's atomic clocks. In the search for dark matter, DQ-mat researchers have recently realised the most accurate search for ultra-light dark matter particles to date. Even though no evidence has yet been found, their nature has been further narrowed down. DQ-mat experiments even reached as far as the International Space Station. Last year, they were involved in the first-ever creation of a quantum gas mixture consisting of two types of atoms. This opens up completely new possibilities for bringing quantum technologies into space that were previously only available on Earth, but also for testing Einstein's equivalence principle, for example. In total, the researchers have published their results in more than 170 scientific papers, given over one hundred lectures and organised 25 workshops and conferences.
The Collaborative Research Centre 1227: Designed Quantum States of Matter (DQ-mat) - Production, Manipulation and Detection for Metrological Applications and Tests of Fundamental Physics is based at Leibniz Universität Hannover. The joint partner is Germany's national metrology institute, the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, as well as the DLR Institute for Satellite Geodesy and Inertial Sensors in Hanover in the third funding period. The third and final funding period runs until the end of June 2028.
