What is a coherent quantum state?

What is a coherent quantum state?

In physics, specifically in quantum mechanics, a coherent state is the specific quantum state of the quantum harmonic oscillator, often described as a state which has dynamics most closely resembling the oscillatory behavior of a classical harmonic oscillator.

What is spin coherent state?

Spin states of maximal projection along some direction in space are called (spin) coherent, and are, in many aspects, the “most classical” available. For any spin s, the spin coherent states form a 2-sphere in the projective Hilbert space \mathbb{P} of the system.

Are coherent states pure states?

It is shown that all pure states whose P representations are nonnegative definite and no more singular than a delta function are coherent states.

Why are coherent states important?

Coherent state can become a useful and important subject in physics because of its three unique properties: the coherence, the overcompleteness and the intrinsic geometrization. These unique properties, in certain contents, are fundamental to field theory.

What is a coherent field?

A light field is called coherent when there is a fixed phase relationship between the electric field values at different locations or at different times. Partial coherence means that there is some (although not perfect) correlation between phase values.

What is coherent passage?

b : having clarity or intelligibility : understandable a coherent person a coherent passage. 2 : having the quality of holding together or cohering especially : cohesive, coordinated a coherent plan for action. 3a : relating to or composed of waves having a constant difference in phase coherent light.

What is thermal state?

The situation changes if one wants to describe states of a system at non-zero temperature (thermal states), i.e. states of a system in thermal equilibrium with a reservoir. The stability of the system is now guaranteed by the reservoir and there is no need of the energy spectral condition.

Is the ground state a coherent state?

So the ground state of the system is a coherent state with parameter z=0.

Are photons coherent?

Coherent light is a beam of photons (almost like particles of light waves) that have the same frequency and are all at the same frequency. In lasers, waves are identical and in phase, which produces a beam of coherent light.

What are coherent sources in physics?

In physics, two wave sources are coherent if their frequency and waveform are identical. Coherence is an ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference. Two waves are said to be coherent if they have a constant relative phase.

What is meant by coherent in physics?

coherence, a fixed relationship between the phase of waves in a beam of radiation of a single frequency. Two beams of light are coherent when the phase difference between their waves is constant; they are noncoherent if there is a random or changing phase relationship.