Laser Creates Quantum Whirlpool

Quantus347 writes: Physicists at The Australian National Univ. (ANU) have engineered a spiral laser beam and used it to create a whirlpool of hybrid light-matter particles called polaritons. Polaritons are hybrid particles that have properties of both matter and light. The ability to control polariton flows in this way could aid the development of completely novel technology to link conventional electronics with new laser- and fiber-based technologies. Polaritons form in semiconductors when laser light interacts with electrons and holes (positively charged vacancies) so strongly that it is no longer possible to distinguish light from matter.

Comments

Re:I thought the distinction was arbitrary already

[students]

Matter has mass. Light has no mass. That's a pretty significant distinction. A polariton's mass can change continuously as a function of energy from zero to about twice the electron mass.

The summary is a little odd. A hole is not a charged vacancy. A vacancy typically refers to a fixed (at low temperatures) location where an atom is missing in the lattice of a crystal. A hole is a mobile positive charge with mass similar to the electron mass.

(Recently finished my PhD studying polaritons and vacancies.)

Re:I thought the distinction was arbitrary already

[Lord Crc]

The one scientists use today: invariant mass aka rest mass.

http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html

Re:I thought the distinction was arbitrary already

[students]

The rest mass is the right mass to talk about in nearly all situations, rather than the relativistic mass.