Such a clock would keep perfect time even after the Universe dies

Sep 25, 2012 06:54 GMT  ·  By
4D crystals will enable instruments such as a clock that will keep perfect time forever, or a device that opens new dimensions into quantum phenomena such as emergence and entanglement
   4D crystals will enable instruments such as a clock that will keep perfect time forever, or a device that opens new dimensions into quantum phenomena such as emergence and entanglement

Researchers at the US Department of Energy's (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) have announced recently that they plan to lead an international collaboration of scientists in developing the world's first space-time crystal.

Also known as a 4D crystal, such a device displays a periodic structure in both space and time, meaning that it could be fashioned into a clock so precise that it would keep perfect track of time even after the death of the Universe.

According to the research group, there are also significant practical and important scientific applications for putting together such a crystal. Thus far, the device has only existed in theoreticians' minds, and was never developed in real life.

The crystals could for example be used to resolve a series of many-body problem of physics, such as studying the complex behaviors and physical properties that arise from interactions between numerous individual particles.

Conducting such studies quickly becomes an intractable problem even for the world's most advanced supercomputers, due to the huge numbers of possibilities involved. In addition, 4D crystals could be used to study quantum entanglement and other phenomena at the elementary particle scale.

Berkeley Lab scientists have already proposed the experimental design of a space-time crystal. They say that the device could consist of an electric-field ion trap, which would operate based on the Coulomb repulsion force that occurs between particles of identical electrical charge.

“The electric field of the ion trap holds charged particles in place and Coulomb repulsion causes them to spontaneously form a spatial ring crystal. Under the application of a weak static magnetic field, this ring-shaped ion crystal will begin a rotation that will never stop,” investigator Xiang Zhang explains.

“The persistent rotation of trapped ions produces temporal order, leading to the formation of a space-time crystal at the lowest quantum energy state,” adds the expert, who holds an appointment as a faculty scientist with the Berkeley Lab Materials Sciences Division (MSD), and also led this research.

What this means is that a clock based on this crystal would be able to keep going even after the Universe reaches thermodynamic equilibrium – known among experts as heat-death.

“The space-time crystal would be a many-body system in and of itself. As such, it could provide us with a new way to explore classic many-body questions physics question,” Berkeley Lab expert and study coauthor, Tongcang Li, explains.

The new study was partially funded by the US National Science Foundations (NSF) Nanoscale Science and Engineering Center.