Researchers have realized a new "time rondeau" crystal that is disordered within individual drive cycles but repeats a stroboscopic state across cycles. Using nitrogen-vacancy centers in diamond to hyperpolarize nearby 13C nuclear spins, the team drove the system with structured, non-periodic pulse sequences and observed oscillations lasting over four seconds. Sampled once per cycle the system returned to the same state, showing long-range temporal order amid short-time chaos. The work, published in Nature Physics, demonstrates programmable temporal ordering and suggests new directions for driven quantum matter.
Scientists Create a 'Time Rondeau' Crystal — Order Emerging from Short-Term Chaos
Researchers have realized a new "time rondeau" crystal that is disordered within individual drive cycles but repeats a stroboscopic state across cycles. Using nitrogen-vacancy centers in diamond to hyperpolarize nearby 13C nuclear spins, the team drove the system with structured, non-periodic pulse sequences and observed oscillations lasting over four seconds. Sampled once per cycle the system returned to the same state, showing long-range temporal order amid short-time chaos. The work, published in Nature Physics, demonstrates programmable temporal ordering and suggests new directions for driven quantum matter.
02:16 AM, 11/16/2025Science
Scientists Create a 'Time Rondeau' Crystal That Blends Chaos and Rhythm
Researchers have engineered a new kind of time crystal — dubbed a time rondeau crystal — whose motion is chaotic within each drive cycle but exhibits a repeating stroboscopic pattern when sampled across cycles. The work reveals a previously unknown form of temporal order in driven quantum systems, where structured but non-periodic drives produce long-lived repetition despite short-time disorder.
The international team, led by Leo Joon Il Moon (University of California, Berkeley) and Paul Schindler (Max Planck Institute for the Physics of Complex Systems), reports experiments using nitrogen-vacancy (NV) centers in diamond. By optically exciting the NV centers, the group hyperpolarized nearby carbon-13 (13C) nuclear spins and then drove them with precisely timed pulse sequences generated by a programmable arbitrary-waveform generator. The pulse sequences ranged from periodic to intentionally structured but non-periodic patterns.
Monitoring hundreds of drive cycles, the researchers observed oscillations that sometimes persisted for more than four seconds before decaying. Although the spins showed disorder and complex micromotion within individual cycles, the system returned to the same state at the start of each cycle when sampled stroboscopically — producing robust long-range temporal order on longer timescales.
"Breaking the periodicity of the drive can lead to new exotic forms of partial temporal order," the authors write. "We reveal the existence of new types of temporal order, arising from non-periodic but structured drives."
The team coined the term "rondeau" by analogy with a musical form (rondo/rondeau) in which a recurring theme alternates with contrasting episodes. In the experiment the recurring stroboscopic state plays the role of the theme, while the short-time disorder provides the contrasting variation.
To demonstrate control and programmability, the researchers even encoded an ASCII line of text — "Experimental observation of a time rondeau crystal. Temporal Disorder in Spatiotemporal Order" — directly into the timing of the pulses. While there is no immediate practical application, the demonstration highlights flexible control over temporal drives and suggests new directions for studying nonequilibrium phases and temporal information encoding.
The results appear in Nature Physics and open experimental paths to investigate coexistence of long-range temporal order and micromotion disorder, with implications for quantum control, time-domain materials, and exploring exotic driven phases of matter.