Quantum electromagnetic field

A more sophisticated approach, based on the interaction of continuous media mediated by the quantum electromagnetic field, was later developed by Lifshitz, but this theory is outside the scope of this present chapter. 

Electronic structure theory describes the motions of the electrons and produces energy surfaces and wavefiinctions. The shapes and geometries of molecules, their electronic, vibrational and rotational energy levels, as well as the interactions of these states with electromagnetic fields lie within the realm of quantum stnicture theory. 

Altliough a complete treatment of optical phenomena generally requires a full quantum mechanical description of tire light field, many of tire devices of interest tliroughout optoelectronics can be described using tire wave properties of tire optical field. Several excellent treatments on tire quantum mechanical tlieory of tire electromagnetic field are listed in [9]. 

Quantization of the Electromagnetic Field.—Instead of proceeding as in the previous discussion of spin 0 and spin particles, we shall here adopt essentially the opposite point of view. Namely, instead of formulating the quantum theory of a system of many photons in terms of operators and showing the equivalence of this formalism to the imposition of quantum rules on classical electrodynamics, we shall take as our point of departure certain commutation rules which we assume the field operators to satisfy. We shall then show that a... 

Before embarking on the problem of the interaction of the negaton-positon field with the quantized electromagnetic field, we shall first consider the case of the negaton-positon field interacting with an external, classical (prescribed) electromagnetic field. We shall also outline in the present chapter those aspects of the theory of the S-matrix that will be required for the treatment of quantum electrodynamics. Section 10.4 presents a treatment of the Dirac equation in an external field. 

According to the Dirac equation the 2Sm and 2P1/2 states coincide. It was, however, observed by Lamb and Rutherford that the 2level shift, one must take into account the quantum aspect of the electromagnetic field as well as those of the negaton-positon field. 

Eigenstates of a crystal, 725 Eigenvalues of quantum mechanical angular momentum, 396 Electrical filter response, 180 Electrical oscillatory circuit, 380 Electric charge operator, total, 542 Electrodynamics, quantum (see Quantum electrodynamics) Electromagnetic field, quantization of, 486, 560... 

Abstract The statistical properties of the electromagnetic field find their origin in its quantum nature. While most experiments can be interpreted relying on classical electrodynamics, in the past thirty years, many experiments need a quantum description of the electromagnetic field. This gives rises to distinct statistical properties. 

Statistical properties of light are described within the framework of quantum optics which is based on a quantized description of the electromagnetic field. In section 21.2 we will depict specific experimenfs which have been performed fo show fhaf a quanfum description is necessary in some cases. We will describe in Section 21.3 fhe sfandard fools for fhe analysis of fhe sfafisfical properties of lighf and give fhe resulfs obfained for a number of sources. 

A quantum mechanical expression for p can be straight forwardly obtained from perturbation theory (with dipolar perturbation coupling of the molecule with the electromagnetic field). 

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