A new breakthrough has enabled physicists to create a beam of atoms that behaves similarly to a laser, and could theoretically last “forever”.
Ultimately, this could mean that the technology is on its way to practical application, although there are still important limitations.
However, this is a huge step forward for what is known as an “atomic laser” – a single wave beam made of atoms that could one day be used to test fundamental physical constants and micro-engineering technology.
The corn laser has been around for a minute. The first atomic laser was created by a team at MIT Physicists 1996† The concept sounds pretty simple: just as conventional light-based lasers consist of photons that move in synchrony with their waves, lasers made of atoms require their wave-like nature to be aligned before mixing as a beam.
However, as with many things in science, it is easier to visualize concepts than to perceive them. In the laser atom root, a. he is Situation Call Bose Einstein condenseror BEC.
BEC is generated by cloud cooling from bosons to break above absolute zero. At such low temperatures, the atoms sink to the lowest possible energy state without stopping completely.
When they reach these low energies, the quantum properties of the particles cannot interfere with each other; They get close enough to create a kind of interference, which results in a cloud of highly dense atoms that behave like a single “super atom,” or wave of matter.
However, BECs are a bit of a contradiction. He is very weak. Even light can destroy BEC. Since the atoms in BEC are Optical laser cooledThis usually means that BEC is short-lived.
Atomic laser scientists have so far been able to realize that it is pulsating rather than versatile; Only one pulse is fired before a new BEC is generated.
To create a continuous BEC, a team of researchers from the University of Amsterdam in the Netherlands realized that something had to change.
“In previous experiments, the gradual cooling of the atoms was done in one place. In our setup, we decided not to spread the cooling steps in time, but in space: we let the atoms move as they go through the successive cooling steps.” Physicist Florian Schreck explained†
“Ultimately, the ultra-cold atoms get to the heart of the experiment, where they can be used to create coherent matter waves in the BEC. But while they use these atoms, the new atoms are already well on their way to regenerating the BEC. That way we can keep the process going – basically forever.” “.
This “heart of the experiment” is the trap that protects the BEC from light, a tank that can be constantly refilled during the experiment.
Protecting BEC from light from a cooling laser, while simple in theory, was more difficult in practice. There were not only technical obstacles, but also bureaucratic and administrative obstacles.
“When we moved to Amsterdam in 2013, we started with a leap of faith, borrowing money, an empty room and a fully funded team of personal grants,” Physicist Chun Chia Chen said:who led the search.
“Six years later, in the early hours of Christmas morning 2019, the experiment was finally complete. We had an idea to add an extra laser beam to solve a final technical problem, and instantly every photo we took showed BEC, the first continuous wave of BEC.”
Now that the first part of the continuous atomic laser has been reached – the “continuous atom” part – the team said the next step is to maintain a steady atomic beam. They can achieve this by bringing the atoms into an unconfined state, and extracting a diffuse wave out of matter.
Using strontium atoms, a popular choice for BECs, the possibility opens up exciting opportunities, they said. For example, atomic interferometry with strontium BECs can be used to conduct research in relativity and quantum mechanics, or gravitational waves†
“Our experiment is the material wave analogue of a continuous wave optical laser with fully reflective cavity mirrors,” In their paper, the researchers wrote:†
“This proof-of-principle demonstration provides a new, hitherto missing piece of atomic optics, enabling the construction of coherent continuous wave devices.”
The search was published in nature of mood†
