Researchers from the Institute for Quantum Information and Matter (California Institute of Technology) have discovered the first three-dimensional quantum-liquid crystal – a new material state that perhaps can be used in future ultra-fast quantum computers. The discovery of this new material state, which can be considered as the quantum-equivalent of a liquid crystal, is probably just the tip of the iceberg: in principle a large number of classes of these quantum-liquid crystals could exist.

Liquid crystals fall somewhere in between liquids and solids; they consist of molecules, which can move freely like in a liquid, but all have the same orientation. In nature, these liquid crystals can be found in biological cell membranes; and of course we are familiar with them from the ubiquitous LC-Displays
In a ‘quantum’-liquid crystal the electrons behave as in the molecules of a ‘classic’ liquid crystal. In other words: the electrons are free to move, but exhibit a preferential direction of movement. This behavior was first demonstrated in 1999 in two-dimensional quantum-liquid crystals; the behavior of the electrons in the newly discovered 3D-variant are possibly even stranger. The electrons do not only distinguish between x-, y- and z-axis, but they also have different magnetic characteristics depending along which axis they move back and forth.

The 3D quantum-liquid crystals could play a role in the technology that is called spintronics, where the spin direction of electrons can be utilized to create more efficient computer chips. The discovery could also be useful for the development of quantum computers: ‘normal’ quantum states are extremely fragile, but this problem could potentially be solved using ‘topological superconductors’ based on 3D quantum-liquid crystals.