Physicists from the Cavendish Laboratory in Cambridge have created the primary two-dimensional version of the Bose glass, a novel phase of matter that challenges statistical mechanics. The small print of the study have been published in Nature.
Because the name suggests, the Bose glass has some glassy properties and inside all of it particles are localised. Because of this each particle within the system sticks to itself, not mixing with its neighbours. If coffee was localised, then when stirring milk into the coffee, the intricate pattern of black and white stripes would remain ceaselessly, as a substitute of washing out to a median.
To create this recent phase of matter, the group overlapped several laser beams to create a quasiperiodic pattern, a pattern that’s long-range ordered like a standard crystal, but not periodic, meaning that, like a Penrose tiling, it never repeats. When filling the resulting structure with ultracold atoms cooled to nanokelvin temperatures — near absolute zero, the atoms formed the Bose glass.
“Localisation just isn’t only considered one of the hardest nuts to crack in statistical mechanics, it will possibly also help to advance quantum computing,” said Professor Ulrich Schneider, Professor of Many-Body Physics on the Cavendish Laboratory, who led the study. Since a localised system wouldn’t mix with its surroundings, quantum information stored in a localised system could be preserved for a lot longer.
“A giant limitation of enormous quantum systems is that we won’t model them on a pc,” said Schneider. “To accurately describe the system, we’ve got to think about all its particles and all their possible configurations, a number that grows in a short time. Nonetheless, we now have a real-life 2D example which we are able to directly study and observe its dynamics and statistics.”
Schneider and his team deal with research into quantum simulation and quantum many-body dynamics. They use ultracold atoms to check many-body effects that, within the absence of a big full quantum computer, can’t be simulated numerically.
Fairly often, this problem simplifies significantly since the system will all the time loosen up right into a thermal state through which only the temperature of the system is vital and most other details vanish. That is known as being ergodic and forms the premise of statistical mechanics, considered one of the pillars of how we understand matter. “For example, simply knowing the quantity of milk poured in is sufficient to predict the ultimate color of our coffee after a protracted stirring,” explained Schneider. “If we wish to predict the complete structure of white and dark swirls throughout the stirring, nonetheless, it is important to know where the milk was poured in and the way the stirring is completed precisely.”
Interestingly, the Bose glass appears to be non-ergodic. Because of this it doesn’t ‘forget its details’, subsequently modelling it should require all the main points. This makes it a first-rate candidate for many-body localisation.
“It is a long-term aspiration to search out a system or material that has many-body localisation,” said Dr Jr-Chiun Yu, the primary writer of the study. “Such a fabric would offer many recent possibilities, not just for fundamental studies, but additionally for constructing quantum computers, as quantum information stored in such a system should remain more local and never leak out into its environment — a process called ‘decoherence’ that plagues many current quantum computing platforms.”
Within the experiment, the researchers observed a surprisingly sharp phase transition from a Bose glass to a superfluid, akin to how ice melts when the temperature increases. “A superfluid is a fluid that flows with none resistance,” said Dr Bo Song, a former Postdoctoral Research Associate in Cambridge and now an Assistant Professor at Peking University, who contributed to the research. “Imagine particles swimming through a superfluid; there could be no friction, and the fluid wouldn’t slow them down. This property, called superfluidity, is closely related to superconductivity. Together with one other quantum phase, the Mott insulator, the newly observed Bose glass and the superfluid make up the bottom states of the Bose-Hubbard model that describes the physics of bosons in interacting and disordered system.”
Bose glasses and superfluids are distinct phases of matter like ice and liquid water. Nonetheless, like ice cubes in a cup of water, the atoms of their system can form each phases throughout the same experiment. The experimental results, confirming recent theoretical predictions, reveal how the Bose glass forms and evolves, so now the scientists can start considering of applications for it.
Nonetheless, though there are exciting opportunities for the longer term, Schneider believes we must always exercise caution. “There are various things we still don’t understand concerning the Bose glass and its potential connection to many-body localisation, each regarding their thermodynamics in addition to dynamical properties. We must always first deal with answering more of those questions before we try to search out uses for it,” concluded Schneider.
