First proposed in the 1920s by Satyendra Nath Bose and Albert Einstein, the concept of a BEC predicted that particles, when cooled to near absolute zero, could merge into a single quantum state. It wasn’t until the 1990s that scientists at the University of Colorado at Boulder confirmed the theory experimentally. Since then, the BEC has become a key tool for probing the foundations of quantum mechanics, revealing new insights with each technological leap.
This latest advancement, made in partnership with Radboud University in the Netherlands, introduces a BEC composed of diatomic molecules, specifically sodium-cesium pairs, at an astonishing temperature just five nanoKelvin above absolute zero. The most significant feature of this condensate is its dipolar nature, meaning the molecules have both positive and negative charges, making them highly interactive and controllable within quantum systems.
Using Microwaves To Cross The BEC Threshold
To reach this new state, the research team employed a method that used two distinct microwave fields. According to Popular Mechanics, this technique allowed the molecules to cross the “BEC threshold” more effectively than previous methods. Microwaves, commonly associated with heating, served instead as protective barriers: they prevented “lossy collisions” by shielding the molecules, which contributed to overall cooling.
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Physicist Tijs Karman from Radboud University explained that the second microwave field was a key improvement over their earlier 2023 experiment. “We’ve come up with schemes to control interactions, tested these in theory, and implemented them in the experiment,” Karman stated, noting how rewarding it was to see the theoretical models brought to life in the lab.
This dual-microwave approach extended the condensate’s stability, offering scientists an opportunity to observe and manipulate it for longer than previously possible. According to Columbia postdoctoral researcher Ian Stevenson, this control over dipolar interactions paves the way for creating new quantum phases and exploring more complex behaviors within ultracold systems.
Two Seconds Of Quantum Stability
In the field of quantum research, stability is a rare commodity. The newly created BEC’s lifespan, two full seconds, is considered remarkably long, giving researchers a precious window to study its behavior in depth. Within that time frame, the BEC remains coherent, meaning all particles in the condensate act as one indistinguishable entity.
The sodium-cesium molecular pair was selected specifically for its suitability in forming a dipolar BEC. This dipole feature allows scientists to exert finer control over the interactions between particles by manipulating external electric or magnetic fields.
This level of precision has not been possible in previous experiments involving atomic BECs. The dipolar BEC opens new possibilities for observing how particles behave in structured environments and for testing theories that had remained inaccessible due to technical limitations.
Gateway To Exotic Phases Of Matter
The creation of this dipolar BEC is not only a technical achievement, it represents an open door to a vast range of exotic quantum matter. According to the published study, the condensate may serve as a platform for realizing dipolar spin liquids, self-organized crystal phases, and exotic dipolar droplets, which are states of matter that scientists have long theorized but struggled to produce experimentally.
These possibilities stem from the unprecedented degree of interaction control afforded by the dipolar nature of the BEC. As Jun Ye, a scientist at UC-Boulder, noted, the ability to control quantum interactions at such a precise level could significantly impact the field of quantum chemistry.
For researchers involved in quantum simulations and condensed matter experiments, this development marks a significant turning point. The method’s effectiveness also suggests that similar techniques might be applied to other molecular systems in the future, offering a roadmap for further exploration of quantum states.