<p> In a first, scientists have created time crystals - a new phase of matter that may have applications in quantum computers.<br /><br /></p>.<p>Just as crystals have an atomic structure that repeats in space, time crystals also have a structures that repeats in time. They are kicked periodically, sort of like tapping Jell-O repeatedly to get it to jiggle.<br /><br />Norman Yao from University of California, Berkeley in the US found exactly how to make and measure the properties of such a crystal and even predicted what the various phases surrounding the time crystal should be - akin to the liquid and gas phases of ice.<br /><br />Researchers from the University of Maryland and Harvard University in the US followed Yao's blueprint and have created the first-ever time crystals.<br /><br />They are the first of a large class of new materials that are intrinsically out of equilibrium, unable to settle down to the motionless equilibrium of, for example, a diamond or ruby.<br /><br />"This is a new phase of matter, period, but it is also really cool because it is one of the first examples of non-equilibrium matter," said Yao.<br /><br />"For the last half-century, we have been exploring equilibrium matter, like metals and insulators. We are just now starting to explore a whole new landscape of non-equilibrium matter," he added.<br /><br />The time crystal created by researchers at the University of Maryland employs a conga line of 10 ytterbium ions whose electron spins interact, similar to the qubit systems being tested as quantum computers.<br /><br />To keep the ions out of equilibrium, they alternately hit them with one laser to create an effective magnetic field and a second laser to partially flip the spins of the atoms, repeating the sequence many times. Because the spins interacted, the atoms settled into a stable, repetitive pattern of spin flipping that defines a crystal.<br /><br />Time crystals were first proposed in 2012 by Nobel laureate Frank Wilczek and last year theoretical physicists at Princeton University and UC Santa Barbara's Station Q in the US independently proved that such a crystal could be made.<br /><br />According to Yao, the UC Berkeley group was "the bridge between the theoretical idea and experimental implementation."<br /><br />From the perspective of quantum mechanics, electrons can form crystals that do not match the underlying spatial translation symmetry of the orderly, three-dimensional array of atoms, Yao said.<br /><br />This breaks the symmetry of the material and leads to unique and stable properties we define as a crystal.<br /><br />A time crystal breaks time symmetry. In this particular case, the magnetic field and laser periodically driving the ytterbium atoms produce a repetition in the system at twice the period of the drivers, something that would not occur in a normal system.<br />The study was published in the journal Physical Review Letters.</p>
<p> In a first, scientists have created time crystals - a new phase of matter that may have applications in quantum computers.<br /><br /></p>.<p>Just as crystals have an atomic structure that repeats in space, time crystals also have a structures that repeats in time. They are kicked periodically, sort of like tapping Jell-O repeatedly to get it to jiggle.<br /><br />Norman Yao from University of California, Berkeley in the US found exactly how to make and measure the properties of such a crystal and even predicted what the various phases surrounding the time crystal should be - akin to the liquid and gas phases of ice.<br /><br />Researchers from the University of Maryland and Harvard University in the US followed Yao's blueprint and have created the first-ever time crystals.<br /><br />They are the first of a large class of new materials that are intrinsically out of equilibrium, unable to settle down to the motionless equilibrium of, for example, a diamond or ruby.<br /><br />"This is a new phase of matter, period, but it is also really cool because it is one of the first examples of non-equilibrium matter," said Yao.<br /><br />"For the last half-century, we have been exploring equilibrium matter, like metals and insulators. We are just now starting to explore a whole new landscape of non-equilibrium matter," he added.<br /><br />The time crystal created by researchers at the University of Maryland employs a conga line of 10 ytterbium ions whose electron spins interact, similar to the qubit systems being tested as quantum computers.<br /><br />To keep the ions out of equilibrium, they alternately hit them with one laser to create an effective magnetic field and a second laser to partially flip the spins of the atoms, repeating the sequence many times. Because the spins interacted, the atoms settled into a stable, repetitive pattern of spin flipping that defines a crystal.<br /><br />Time crystals were first proposed in 2012 by Nobel laureate Frank Wilczek and last year theoretical physicists at Princeton University and UC Santa Barbara's Station Q in the US independently proved that such a crystal could be made.<br /><br />According to Yao, the UC Berkeley group was "the bridge between the theoretical idea and experimental implementation."<br /><br />From the perspective of quantum mechanics, electrons can form crystals that do not match the underlying spatial translation symmetry of the orderly, three-dimensional array of atoms, Yao said.<br /><br />This breaks the symmetry of the material and leads to unique and stable properties we define as a crystal.<br /><br />A time crystal breaks time symmetry. In this particular case, the magnetic field and laser periodically driving the ytterbium atoms produce a repetition in the system at twice the period of the drivers, something that would not occur in a normal system.<br />The study was published in the journal Physical Review Letters.</p>