Laser light traps atoms, which enable simulation of solid state systems, which also serves as a base for discovering quantum matter and other new phenomena.
In a metal an electron, depicted by a gray circle, can move to the conduction energy “bands” freely because there is no forbidden region (gap) present.
The Joint Quantum Institute researchers have demonstrated that an optical lattice system displays a brand new quantum state known as a topological semimetal, published in this week’s Advance Online Publication for the journal Nature Physics, that can change phase to form a topological insulator, which serves as an insulator across the majority of the material but serve as conductors along the edges, operating without external magnets. When the atoms fail to interact with each other, an energy band structure emerges representing a semimetal having special properties, allowing it to transform into a topological insulator when the atoms begin to interact. A material’s band structure is the one where bands and gaps characterize allowed and forbidden electron energies. A valence band includes all the allowed energies where a solid is at absolute zero temperature, in which electrons are filled, and are confined to their parent atoms in the solid. A conduction band, placed above, is a zone that can be occupied when the electrons gain energy to travel. This topological semimetal is void of gap, although slightly traced in the energy spectrum.
Researchers started with a semi-metal to show that when particles interact, it disrupts the system, forcing a phase transition and upon adding these interactions the particles began to rotate. The projected experiment employs recognized atomic physics techniques and is exercised for studying condensed matter physics.