PHONONS - SCI & TECH
News: Explained
| Are phonons, particles of sound, quantum too?
What's in the news?
● Physicists
have found that packets of vibrational energy behave like packets of light
energy using a new kind of beam-splitter.
Key takeaways:
Qubits and Quantum Computing:
● Quantum
computers use qubits as their basic
units of information. A qubit can be a particle – like an electron; a
collection of particles; or a quantum system engineered to behave like a
particle.
● Particles
can do funky things that large objects – like the semiconductors of classical
computers – can’t because they are guided by the rules of quantum physics.
● These
rules allow each qubit to have the values
‘on’ and ‘off’ at the same time, for example.
● The
premise of quantum computing is that information can be ‘encoded’ in some
property of the particle, like an electron’s spin, and then processed using
these peculiar abilities.
● As
a result, quantum computers are expected to perform complicated calculations
that are out of reach of the best supercomputers today.
● Other
forms of quantum computing use other units of information.
● For
example, linear optical quantum
computing (LOQC) uses photons, the particles of light, as qubits.
● Just
like different pieces of information can be combined and processed by encoding
them on electrons and then having the electrons interact in different ways,
LOQC offers to use optical equipment – like mirrors, lenses, splitters,
waveplates, etc. – with photons to process information.
What are Phonons?
● Phonons
are the quanta of sound just like a
photon is a quanta or the packet of energy for electromagnetic waves.
Features:
● Phonons
are packets (quasi-particles) of
vibrational energy.
● These
packets of energy behave like particles
in a system.
● When
the grid of atoms that make up the material vibrates, it releases this energy,
and physicists encapsulate it in the form of phonons.
Go back to basics:
Beam-splitters:
● Physicists
have found that packets of vibrational energy (phonons) behave like packets of
light energy using a new kind of beam-splitter.
● Beam-splitters
are used widely in optics research.
● Imagine
a torchlight shining light along a straight line. This is basically a stream of
photons. When a beam-splitter is placed in the light’s path, it will split the
beam into two: i.e. it will reflect 50% of the photons to one side and let the
other 50% pass straight through.