Glauber P representation
Encyclopedia
The Glauber-Sudarshan P-representation is a way of writing down the state of any type of light
using the coherent state
s as a basis. It was developed by George Sudarshan
and later adopted by Roy J. Glauber
(see the references below). It was the subject of a controversy when Glauber was awarded a share of the 2005 Nobel Prize in Physics
for his work in this field and George Sudarshan
's contribution was not recognized.
In this representation, the density matrix
is written as:
where
are the coherent states and 
is a quasi-probability distribution.
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
using the coherent state
Coherent state
In quantum mechanics a coherent state is a specific kind of quantum state of the quantum harmonic oscillator whose dynamics most closely resembles the oscillating behaviour of a classical harmonic oscillator...
s as a basis. It was developed by George Sudarshan
George Sudarshan
Ennackal Chandy George Sudarshan , also E.C.G. Sudarshan, is a prominent Indian American physicist, author, and professor at The University of Texas at Austin.-Early life:...
and later adopted by Roy J. Glauber
Roy J. Glauber
Roy Jay Glauber is an American theoretical physicist. He is the Mallinckrodt Professor of Physics at Harvard University and Adjunct Professor of Optical Sciences at the University of Arizona...
(see the references below). It was the subject of a controversy when Glauber was awarded a share of the 2005 Nobel Prize in Physics
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...
for his work in this field and George Sudarshan
George Sudarshan
Ennackal Chandy George Sudarshan , also E.C.G. Sudarshan, is a prominent Indian American physicist, author, and professor at The University of Texas at Austin.-Early life:...
's contribution was not recognized.
In this representation, the density matrix
Density matrix
In quantum mechanics, a density matrix is a self-adjoint positive-semidefinite matrix of trace one, that describes the statistical state of a quantum system...
is written as:where
are the coherent states and is a quasi-probability distribution.See also
- Nonclassical lightNonclassical lightNonclassical light is any state of light that cannot be described using classical electromagnetism; its characteristics are described by the quantised electromagnetic field and quantum mechanics...
- Wigner quasi-probability distributionWigner quasi-probability distributionThe Wigner quasi-probability distribution is a quasi-probability distribution. It was introduced by Eugene Wigner in 1932 to study quantum corrections to classical statistical mechanics...
- Husimi Q representationHusimi Q representationThe Husimi-Q distribution is a mathematical tool used in physics, and was introduced in 1940. The Q-representation is a quasi-probability distribution commonly used in quantum mechanics and also to represent the quantum state of light. It is used in the field of quantum optics and particularly...
- Nobel Prize controversiesNobel Prize controversiesSubsequent to his death in 1896, the will of Swedish industrialist Alfred Nobel established the Nobel Prizes. Annual prizes were to be awarded for service to humanity in the fields of physics, chemistry, physiology or medicine, literature, and peace. Similarly, the Bank of Sweden Prize in Economic...