Grant: Discovery Grants Program - Individual

During the last 20 years, technologies have been developed that use genuine quantum effects. Most prominently, this includes quantum computing and quantum information. Less well known but equally important examples are: quantum sensing, to search for natural resources or monitor gravitational and electromagnetic forces; and quantum imaging, to enhance image resolution or develop non-destructive imaging techniques. However, this comes at a price; quite generally, quantum technology is more susceptible to external influences such as thermal fluctuations. It needs to be much better insulated from its environment, which is difficult for large systems. This is the main difficulty in building large-scale universal quantum computers, for instance. For this reason, there has been a growing interest in developing hybrid quantum technologies, which involve different quantum systems for different tasks. For instance, atoms are used to store quantum information, and photons to distribute it. In a different approach, technology may use quantum physics for one task and classical physics for another. For instance, there are algorithms that mostly run on a classical computer but use quantum computers to evaluate specific steps. In our research program, we will study how classical systems may be enhanced using quantum physics, and how quantum sensors may be used as part of an otherwise classical device. Our program has two parts. In the first part, we will look at classical systems that already possess a high sensitivity and evaluate whether they could be further improved using quantum effects. A central part of our work will be to develop cancellation schemes that eliminate the detrimental effects of external influences. Our work has started with a study on atomic force microscopes, which scan the surface of biological tissues and other samples with sub-nanometer resolution. We identified a way how to reduce uncertainties in measuring the position of the surface, and how to isolate quantum effects from thermal fluctuations. We will use similar methods to study other nanostructures, such as quantum dots or microscopic electrical circuits. In a second part of the program, we will study interferometer sensors that use atoms and light. They can be located on the Earth's surface, in near-Earth space, or in outer space. In such sensors, the classical path of a particle is probed using quantum interference, which results in high-precision measurement of gravitational and electromagnetic forces. Such sensors have practical applications in the search for natural resources, and to detect the presence of magnetic materials or electromagnetic signals. However, they can also be used for fundamental tests of quantum mechanics, or tests of Einstein's theory of relativity. In both parts, our goal is to bring quantum sensors to the next level by developing noise cancellation schemes and finding synergies between different quantum technologies.