A team of quantum physicists from Innsbruck, Austria, led by ERC curator Francesca Ferlaino, has developed a new technique (Small ultra-cold twisters) to observe vortices in dipole quantum gases. These quantum vortices are considered a strong reflection of the fluid, friction-less atmosphere of a quantum gas, and now they have been detected experimentally for the first time in a gas dipole. Whirlpools are everywhere in nature: moving water can create whirlpools. When the air is convulsing, strong winds can form.
This is also the case in the quantum world, except that many similar vortices are formed at the same time – the vortex is made dense. In many quantum gases, such vortices have already been demonstrated. “It is interesting because such vortices are a clear indication of the lack of friction of quantum air – the so-called super fluidity,” said Francesca Ferlaino of the Department of For Visual Physics at the University of Innsbruck and the Institute for Quantum Optics and Quantum Information says. in the Austrian Academy of Sciences.
Ferlaino and his team are studying gases that contain strong magnetic fields. For such dipolar quantum gases, in which the atoms are strongly bound to each other, quantum vortices cannot be demonstrated so far. The scientists have developed a new method: “We use the direction of our quantum dysprosium gas, whose atoms behave like many small magnets, to move the gas”, Manfred Mark of Francesca Ferlaino explains.
To do this, scientists apply a magnetic field to their quantum gas in such a way that this pancake-like gas initially escapes magnetostriction. This idea, as simple as it is powerful, was born a few years ago from a conceptual project by a group of scientists at the University of Newcastle, led by Nick Parker and including Thomas Bland, author the second part of the story.
“By reversing the magnetic field, we can ignite a quantum gas,” says Lauritz Klaus, first author of the present paper. “If it runs too fast, small vortices form in the quantum gas. This is how the gas tries to balance the angular momentum. At sufficiently high rotational speeds, some vortices form around the magnetic field. These are unique aspects of the quantum dipole and have now been observed for the first time at the University of Innsbruck, Austria.
This new method (Small ultra-cold twisters), now presented in Nature Physics, will be used to study superfluidity in the solid state of quantum solids and liquids. “It is really still an open question of the degree of superfluid character and the newly discovered supersolid says, and this question still remains very little study today.”
