Physicists propose a 'time fluid' model—a new state of matter

Theoretical model of a new state of matter

Physicists from the Max Planck Institute for the Physics of Complex Systems have proposed a theoretical model of an unusual state of matter called a 'discrete time fluid'. In this state, ordered oscillations persist only over limited time intervals. The work has been posted on the arXiv preprint server and has not yet undergone scientific peer review, as reported by Gazeta.Ru.

From time crystals to 'fluid'

The idea builds upon research into time crystals. In an ordinary crystal, the arrangement of atoms repeats in space, whereas in a time crystal, a specific pattern of motion repeats: for example, a system may return to its initial state after two cycles of external influence, even though the influence itself repeats twice as frequently. The authors examined a two-dimensional system of spins—elementary magnetic moments—coupled with an electromagnetic resonator at a non-zero temperature. Thermal fluctuations made the resonator's influence noisy: it remained approximately periodic but could not maintain a single rhythm indefinitely.

Solitons as defects of temporal order

Despite the instability of the influence, the calculations showed that the spins exhibited stable period doubling. Meanwhile, the system randomly switched between two variants of oscillations shifted relative to each other from time to time; the authors described these switches as temporal solitons—defects of temporal order. This resulted in a state where order is preserved over short time intervals but is lost when observed over longer periods. The analogy with a fluid, where neighboring particles are arranged in a certain way but lack the strict spatial lattice found in a crystal, gave the model its name.

What comes next

The 'time fluid' currently exists only in theoretical descriptions and computer simulations. The proposed state is metastable: it can persist for a long time but not necessarily indefinitely. The next step should be to verify whether such a regime can be reproduced in a real physical system. This concerns an unusual organization of oscillations, not the literal flow of matter through time. It is important for the reader to understand the status of the work: it is a preprint, meaning the results have not yet been evaluated by independent scientists, and conclusions may change after peer review. Gazeta.Ru also reminds that a quantum mystery was previously solved, which had baffled physicists for decades.