Quantum computers could give scientists a new way to explore the hidden behaviour of matter

Scientists could have a new way to explore the hidden behaviour of matter, thanks to research involving Queen Mary University of London that uses a quantum computer to carry out a new form of computational spectroscopy. 

Spectroscopy is an important scientific technique used to understand the properties of matter. By analysing how materials and molecules respond to energy or light, researchers can gain insights into their structure and behaviour. Computational approaches can complement these experiments by allowing scientists to investigate and predict properties using theoretical models and simulations. 

However, quantum systems can be exceptionally difficult to model using conventional computers. The new research, published in Nature Communications, develops a generalised approach to quantum computational spectroscopy that allows researchers to study a much broader range of quantum systems. 

The method can be used not only for relatively simple, static systems, but also for systems that are affected by their environment or change over time. The researchers reconstructed a key measure of quantum behaviour using a quantum computing technique known as an ancilla-assisted Hadamard test. The researchers used the method to investigate unusual quantum phenomena, including parity-time symmetry breaking and topological holonomy. These examples demonstrate how quantum computational spectroscopy could provide insights into quantum behaviour that are difficult to access using conventional spectroscopy or existing quantum approaches. 

The work could ultimately be relevant to areas including physics, chemistry and materials science. Computational spectroscopy can help researchers investigate the properties of real or hypothetical materials before they are produced experimentally, with potential applications in areas such as molecular engineering, drug design and advanced materials research. 

Dr Jinzhao Sun, from the School of Physical and Chemical Sciences at Queen Mary University of London, led the theoretical aspect of the study. The research represents a step towards using quantum computers not simply to perform calculations, but as tools for exploring and understanding the behaviour of complex quantum systems. 

As quantum computing technology develops, approaches such as this could provide scientists with new ways to investigate phenomena that are difficult to reproduce or calculate using conventional methods. 

The full paper is available on Nature Communications.