For physicists, it is an exciting time to catch up with the fundamental physics nature of Wigner crystals. This strange form of matter might enable powerful new forms of quantum computing and spintronics. In fact, scientists predicted these crystalline structures created by electrons in two-dimensional systems way back in 1934. In recent years, several experiments have verified their existence, providing a new window into exotic quantum phases of matter.
One type of electron solid, a Wigner crystal, forms when electrons collect at low densities. This eccentric configuration is capable of exhibiting simultaneously conducting and insulating characteristics. This duality is like a ball shooting across a pinball machine. In this new system, some electrons are fixed in place while others can move around without restraint. Researchers are especially enthused by this phenomenon’s implications for emerging technologies.
Such Wigner crystals would have an enormous impact on the emerging field of spintronics. This new field—Rashba science—seeks to control the intrinsic spin of electrons and their associated magnetic moments. Spintronics holds the potential to enhance the memory and logic processing power of nano-electronic devices. Simultaneously, it seeks to reduce electricity use and per-unit generation costs. Writer and researcher Cyprian Lewandowski, an early critic of the concept, asks some interesting questions. He raises questions such as, “What makes something an insulator, conductor, or magnet? How can we transmute something to another state?
The latest studies illustrate the mechanism through which Wigner crystals can partially “melt.” You can picture this process as some electrons remaining localized while others begin to delocalize. This new behavior provides powerful new routes to control many different phases of matter at widely differing conditions. Lewandowski laid out their objectives. We want to be able to predict where interesting phases of matter are going to be, how one state changes into another. “We found some of these quantum knobs to control states of matter. These results promise great strides in the future of experimental research.
During the course of this ping-ponging phase, scientists have discovered key ingredients that govern the emergence of these generalized Wigner crystals. Hitesh Changlani explained the importance of their findings: “In our study, we determined which ‘quantum knobs’ to turn to trigger this phase transition and achieve a generalized Wigner crystal, which uses a 2D moiré system and allows different crystalline shapes to form, like stripes or honeycomb crystals, unlike traditional Wigner crystals that only show a triangular lattice crystal.”
Scanning tunneling images of the Wigner electron density show a beautiful and surprising quantum mechanical effect. In this configuration, each electron holds two bits of quantum information. This property is particularly relevant to applications in large-scale, fault-tolerant quantum computers.
Aman Kumar, another key researcher, expressed confidence in their theoretical understanding: “We’re able to mimic experimental findings via our theoretical understanding of the state of matter.” This new-found partnership between theorists and experimentalists is opening up new realms of discovery in quantum technology and fundamental physics alike.