The study of condensed matter physics, and specifically quantum materials, has exploded over the past two decades, shown by the surge in published academic papers on the topic. The excitement surrounding the unique properties exhibited by these exotic materials is well-founded, as quantum materials promise to spark the next technological revolution.
Strictly speaking all materials exist due to the laws of quantum physics; however, the label of “quantum materials” is given to those materials that exhibit phenomena on the macroscopic scale that cannot be explained by classical physics. Macroscopic quantum characteristics in a material are usually caused by strong electron correlation within the solid giving rise to emergence – collective behaviour on the macroscopic scale that cannot be explained through study of the underlying microscopic particles that make up a solid.
Since the mid-80’s when IBM researchers discovered the first high-temperature superconductor (winning a Nobel Prize in the process), many in the fields of condensed matter physics and materials science have dedicated their research to the exploitation of quantum phenomena exhibited on the macroscopic scale. The 21st century has seen further breakthroughs for quantum materials research, notably in the discovery of giant magnetoresistance and graphene, both of which earned researchers a Nobel Prize.
Quantum Materials in Research Field
The unique electronic, optical and magnetic properties exhibited by quantum materials are of particular interest to researchers, who hope to exploit their novel characteristics in areas such as sensing, information processing and memory, to spearhead a new technological revolution.
For instance, the discovery of graphene and other 2D materials, in which the confinement of electrons to two dimensions has given rise to unique electrical and optical properties, has promised countless applications in fields as wide ranging as flexible electronics, drug delivery and water filtration. Some other technologies emerging due to our increased understanding of quantum materials include Mott insulators, high-temperature superconductivity and quantum communication.
However, possibly the most exciting application is in quantum computing. Quantum computers take advantage of quantum phenomena such as superposition, entanglement and tunnelling to vastly exceed the processing power of regular computers, enabling scientists and businesses alike to solve problems previously considered too complex for even our most sophisticated machines.
Central to the idea of quantum computing is the qubit, which, unlike the conventional bit, can encode information as 0s, 1s or, crucially, both. This exploitation of the superposition of quantum states has huge implications for our efforts to simulate complex systems, such as molecular interactions. The ability of quantum computers to manipulate vast combinations of states at once is expected to produce wide-reaching benefits, from the development of new drugs to artificial intelligence.
The stability of qubits is now of paramount importance to researchers, whose task is to protect the quantum states from perturbations and decoherence caused by the surrounding environment. Researchers are optimistic that quantum materials can once again provide the solution.
The power of quantum computing, and quantum materials as a whole, has not been lost on businesses, with some of the world’s biggest companies dedicating resources to their advancement. Google have collaborated with NASA to form the Quantum AI Lab which aims to pioneer the use of quantum computing for machine learning and, similarly, Microsoft’s Station Q research lab is dedicated to the study of topological quantum computing for its implementation in everyday life.
MIT’s Materials Processing Center Director Carl V. Thompson emphasized the importance of advancements in our understanding of quantum materials when he stated: “Moore’s Law enabled smaller, cheaper, faster electronic devices for five decades, but it will take a new paradigm like quantum materials to make the next technological leap.”