Physicists have long been fascinated by the concept of symmetry breaking, a fundamental principle in physical sciences that underpins the formation of distinct phases of matter. In conventional crystals, spatial symmetry is broken, leading to periodic structures like those seen in diamonds or quartz. But what happens when symmetry breaks in time rather than space?
This question has driven researchers to explore the exotic world of time crystals, where patterns emerge not in three-dimensional space but across the fourth dimension—time itself. Now, scientists have taken this concept a step further by creating a new type of matter known as a time quasicrystal, a discovery that challenges existing understandings of order and periodicity.
Researchers at Washington University in St. Louis, in collaboration with scientists from MIT and Harvard, have successfully created a time quasicrystal. This breakthrough builds on the discovery of discrete time crystals (DTCs), a phase of matter that breaks time-translation symmetry, meaning that particles within the system oscillate at intervals that are longer than those of the driving force.
Research findings have been published in the prestigious journal Physical Review X.
Unlike conventional time crystals, which exhibit a strict, repeating time pattern, a time quasicrystal demonstrates complex, non-repeating time intervals. Much like quasicrystals in materials science, where atomic arrangements are ordered but lack simple repetition, time quasicrystals possess highly structured yet non-periodic rhythms.
Chong Zu, assistant professor of physics at Washington University, explains, “Much like the atoms in a normal crystal repeat patterns in space, the particles in a time crystal repeat patterns over time. The time quasicrystal takes this one step further by introducing multiple frequencies that interact in a precise but non-repetitive way.”
To create this unique phase of matter, the research team utilized a small, millimeter-sized diamond embedded with nitrogen-vacancy (NV) centers. These NV centers were engineered by bombarding the diamond with nitrogen beams, knocking out carbon atoms and leaving atom-sized vacancies. Electrons naturally occupied these spaces, forming a strongly interacting quantum system.
The researchers then applied microwave pulses, inducing oscillations that followed a quasiperiodic pattern rather than a simple, repeated tick. “The microwaves help create order in time,” says Bingtian Ye, co-author of the study. “We used multiple frequencies to create a structure that was organized but not periodic.”
Related Stories
Traditional time crystals, first demonstrated in 2016 at the University of Maryland, rely on periodic driving forces to establish long-lived oscillatory behavior. In contrast, time quasicrystals exhibit more complex dynamics, where the frequencies of oscillation arise from incommensurate interactions rather than simple integer multiples of a base frequency.
Lead author Guanghui He elaborates, “The different dimensions of time quasicrystals vibrate at different frequencies, much like playing a musical chord instead of a single note.”
The research team observed that the time quasicrystal phase was robust, meaning that even when subjected to external perturbations, the system maintained its intricate temporal order. This stability is a critical feature distinguishing a genuine phase of matter from a transient phenomenon.
To quantify this robustness, the team examined the interplay between many-body interactions within the NV spin ensemble and the magnitude of external disturbances, mapping out a detailed phase diagram of time quasicrystals.
By leveraging multiple crystallographic groups of NV centers, the team also demonstrated the possibility of creating even more complex time quasicrystalline phases. One such example was a system with a Z2 × Z2 symmetry, a configuration that introduces additional layers of structure into the emergent time order. “This opens the door for more sophisticated time-based phases of matter,” says Zu.
While time quasicrystals are still in the realm of fundamental research, their discovery has significant implications for various technological applications. One of the most promising uses lies in the field of quantum sensing. Time quasicrystals exhibit extreme sensitivity to external fields, making them potential candidates for ultra-precise quantum sensors that do not require recalibration or an external power source. “Because time crystals can theoretically tick forever without losing energy, they could serve as long-lasting quantum sensors,” Zu notes.
Another exciting application is in timekeeping. Today’s quartz oscillators in watches and electronics require periodic calibration due to frequency drift. A time quasicrystal, by contrast, could maintain a precise and stable oscillation without external correction.
Additionally, because time quasicrystals can incorporate multiple frequencies, they could enable new methods for measuring and analyzing quantum systems over extended periods.
Perhaps the most ambitious potential use of time quasicrystals is in quantum computing. Since quantum information is highly fragile and susceptible to decoherence, finding a way to store and maintain quantum memory is a critical challenge.
Zu explains, “Time crystals could act as a quantum analog of RAM, providing a method to store quantum information over long durations. We’re still far from achieving this, but this discovery represents a crucial step forward.”
As research into time quasicrystals continues, scientists are eager to explore their properties further. Future work will involve fine-tuning the interactions within these systems to better control their behavior. Additionally, researchers aim to investigate whether time quasicrystals can be engineered in other quantum materials beyond NV centers in diamond.
Zu and his colleagues are optimistic about the future of this new phase of matter. “We believe we are the first group to create a true time quasicrystal,” He states. “This is just the beginning of understanding how time can be structured in entirely new ways.”
Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.
Like these kind of feel good stories? Get The Brighter Side of News’ newsletter.
The post Time Crystals: A New Frontier in Quantum Physics appeared first on The Brighter Side of News.
Leave a comment
You must be logged in to post a comment.