Quantum world is the theory of the microscopic world that describes particles, atoms, and molecules at both elegant and mysterious scales. It is a world where particles can exist in two places at once and can react to each other over vast distances. This world may seem as dinky. Recently, researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) have theoretically described two quantum states that are extraordinary in both the physics that define them and their visual appeal.
Scientists have invented a complex quantum system i.e., a quantum necklace that simulates classical physics and a spellbinding necklace-like state. In real, the search for these two states starts with a doughnut-shaped container housing a rotating superfluid.
The superfluid is nothing but a fluid that moves with no friction. It consists of Bose-Einstein condensates (BECs) comprising particles without charge that are cold down near zero degrees Kelvin.
At this temperature, these particles started to exhibit strange properties. For example, they started clumping together and finally became indistinguishable from one another. Hence they become a single entity and thus move as one.
But, in actuality this vertiginous superfluid operates at a quantum scale, thus, the physical characteristics of its rotation are not those seen in the classical world.
OIST Professor Thomas Busch explained, “In a superfluid…things which are very far away [from the center] move really slowly, whereas things [that] are close to the center move very fast. This is what is happening in the superfluid doughnut.”
Dr. Angela White said, “The shortest boundary [between the components] is in the radial direction. The two components separate into different halves of the doughnut along this boundary, which is created by passing through the doughnut’s radius. In this configuration, they will use less energy to remain separated than they would via any other.”
In the immiscible or unmixable configuration, the boundary between the two superfluids must remain aligned along the radial direction. Thus, the superfluid must rotate like a classical object to maintain a low-energy state.
If in the case, the boundary, the superfluids continued to rotate faster on the inside, then the two semicircles would start to twist. And thus, they will need high energy in order to get separate.
The result is a sort of classical physics mimicry, where the system appears to jump into the classical realm, facilitated by complex quantum mechanical behavior.
In this stage, the superfluid inside doughnut has reached its first extraordinary state that shows classical rotation. But there was one more step required to transform this system into the necklace.
To do so, they involved particles that have no charge or spin. When coupling these particles, the semicircles in doughnut break into multiple alternating parts and forms the necklace configuration.
By digging further into its composition, scientists found that the number of “pearls” in the necklace depends on the strength of the spin-orbit coupling.
According to researchers, they have found a way to create a stable quantum necklace.