Can matter cycle through shapes eternally? : Nature News & Comment

Can matter cycle through shapes eternally? : Nature News & Comment: Wilczek's latest paper outlines another, perhaps simpler, scheme for making a time crystal. It starts with two chunks of superconductor connected by a nonsuperconductor. This device,called a Josephson junction, can create fluctuations in currents if an external voltage is applied. Wilczek argues that merely breaking the contact between the superconductors could create the type of fluctuations that characterize a time crystal.

Physicist proves impossibility of quantum time crystals

Physicist proves impossibility of quantum time crystals: Bruno explains that this proof should not come as a surprise, since a 1964 theory by another Nobel Laureate, Walter Kohn, shows that an insulator is completely insensitive to a magnetic flux. Since quantum time crystals are modeled as ring-shaped Wigner crystals, and Wigner crystals are insulators, attempting to show that a magnetic flux can cause such a system to rotate is, as Bruno writes, "a hopelessly doomed endeavor."