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Rabi Problem
The Rabi problem concerns the response of an atom to an applied harmonic electric field, with an applied frequency very close to the atom's natural frequency. It provides a simple and generally solvable example of light–atom interactions and is named after Isidor Isaac Rabi. Classical Rabi problem In the classical approach, the Rabi problem can be represented by the solution to the driven damped harmonic oscillator with the electric part of the Lorentz force as the driving term: : \ddot_a + \frac \dot_a + \omega_a^2 x_a = \frac E(t, \mathbf_a), where it has been assumed that the atom can be treated as a charged particle (of charge ''e'') oscillating about its equilibrium position around a neutral atom. Here ''xa'' is its instantaneous magnitude of oscillation, \omega_a its natural oscillation frequency, and \tau_0 its natural lifetime: : \frac = \frac, which has been calculated based on the dipole oscillator's energy loss from electromagnetic radiation. To apply this to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atom
Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element. Atoms are extremely small, typically around 100 picometers across. A human hair is about a million carbon atoms wide. Atoms are smaller than the shortest wavelength of visible light, which means humans cannot see atoms with conventional microscopes. They are so small that accurately predicting their behavior using classical physics is not possible due to quantum mechanics, quantum effects. More than 99.94% of an atom's mass is in the nucleus. Protons hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-state Quantum System
In quantum mechanics, a two-state system (also known as a two-level system) is a quantum system that can exist in any quantum superposition of two independent (physically distinguishable) quantum states. The Hilbert space describing such a system is two-dimensional. Therefore, a complete basis spanning the space will consist of two independent states. Any two-state system can also be seen as a qubit. Two-state systems are the simplest quantum systems that are of interest, since the dynamics of a one-state system is trivial (as there are no other states in which the system can exist). The mathematical framework required for the analysis of two-state systems is that of linear differential equations and linear algebra of two-dimensional spaces. As a result, the dynamics of a two-state system can be solved analytically without any approximation. The generic behavior of the system is that the wavefunction's amplitude oscillates between the two states. A well known example of a two-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Rabi Oscillation
A vacuum Rabi oscillation is a damped oscillation of an initially excited atom coupled to an electromagnetic resonator or cavity in which the atom alternately emits photon(s) into a single-mode electromagnetic cavity and reabsorbs them. The atom interacts with a single-mode field confined to a limited volume ''V'' in an optical cavity. Spontaneous emission is a consequence of coupling between the atom and the vacuum fluctuations of the cavity field. Mathematical treatment A mathematical description of vacuum Rabi oscillation begins with the Jaynes–Cummings model, which describes the interaction between a single mode of a quantized field and a two level system inside an optical cavity. The Hamiltonian for this model in the rotating wave approximation is :\hat_ = \hbar \omega \hat^\hat +\hbar \omega_0 \frac +\hbar g \left(\hat\hat_+ +\hat^\hat_-\right) where \hat is the Pauli z spin operator for the two eigenstates , e \rangle and , g\rangle of the isolated two level s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rabi Frequency
The Rabi frequency is the frequency at which the Probability amplitude, probability amplitudes of two atomic electron transition, atomic energy levels fluctuate in an oscillating electromagnetic field. It is proportional to the transition dipole moment of the two levels and to the amplitude (''not'' Irradiance, intensity) of the electromagnetic field. Population transfer between the levels of such a 2-level system illuminated with light exactly resonant with the difference in energy between the two levels will occur at the Rabi frequency; when the incident light is detuned from this energy difference (detuned from resonance) then the population transfer occurs at the #Generalized Rabi frequency, generalized Rabi frequency. The Rabi frequency is a semiclassical concept since it treats the atom as an object with quantized Energy level, energy levels and the electromagnetic field as a continuous wave. In the context of a nuclear magnetic resonance experiment, the Rabi frequency is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
