quantum

(noun)

The smallest possible, and therefore indivisible, unit of a given quantity or quantifiable phenomenon.

Related Terms

Examples of quantum in the following topics:

  • Implications of Quantum Mechanics

    • Quantum mechanics has also strongly influenced string theory.
    • The application of quantum mechanics to chemistry is known as quantum chemistry.
    • Researchers are currently seeking robust methods of directly manipulating quantum states.
    • Another topic of active research is quantum teleportation, which deals with techniques to transmit quantum information over arbitrary distances.
    • Explain importance of quantum mechanics for technology and other branches of science

  • Quantum Numbers

    • Quantum numbers provide a numerical description of the orbitals in which electrons reside.
    • Formally, the dynamics of any quantum system are described by a quantum Hamiltonian (H) applied to the wave equation.
    • The average distance increases with n, thus quantum states with different principal quantum numbers are said to belong to different shells.
    • The second quantum number, known as the angular or orbital quantum number, describes the subshell and gives the magnitude of the orbital angular momentum through the relation.
    • The value of the mℓ quantum number is associated with the orbital orientation.

  • Philosophical Implications

    • This is due to the quantum mechanical principle of wave function collapse.
    • One of the most bizarre aspect of the quantum mechanics is known as quantum entanglement.
    • Quantum entanglement occurs when particles interact physically and then become separated, while isloated from the rest of the universe to prevent any deterioration of the quantum state.
    • This seemingly puts a limit on the speed at which information can be transmitted. ) Quantum entanglement is the key element in proposals for quantum computers and quantum teleportation.
    • Formulate the Copenhagen interpretation of the probabilistic nature of quantum mechanics

  • Indeterminacy and Probability Distribution Maps

    • Quantum mechanics provides a recipe for calculating this probability distribution.
    • An adequate account of quantum indeterminacy requires a theory of measurement.
    • Many theories have been proposed since the beginning of quantum mechanics, and quantum measurement continues to be an active research area in both theoretical and experimental physics.
    • In quantum mechanical formalism, it is impossible that, for a given quantum state, each one of these measurable properties (observables) has a determinate (sharp) value.
    • In the world of quantum phenomena, this is not the case.

  • The Uncertainty Principle

    • Heisenberg offered such an observer effect at the quantum level as a physical explanation of quantum uncertainty.
    • It has since become clear, however, that the uncertainty principle is inherent in the properties of all wave-like systems and that it arises in quantum mechanics simply due to the matter-wave nature of all quantum objects.
    • Since the uncertainty principle is such a basic result in quantum mechanics, typical experiments in quantum mechanics routinely observe aspects of it.
    • These include, for example, tests of number-phase uncertainty relations in superconducting or quantum optics systems.
    • One of the most-oft quoted results of quantum physics, this doozie forces us to reconsider what we can know about the universe.

  • Photochemistry

    • This "photoequivalence law" was derived by Albert Einstein during his development of the quantum (photon) theory of light.
    • The efficiency with which a given photochemical process occurs is given by its Quantum Yield (Φ).
    • Since many photochemical reactions are complex, and may compete with unproductive energy loss, the quantum yield is usually specified for a particular event.
    • The quantum yield of these products is less than 0.2, indicating there are radiative (fluorescence & phosphorescence) and non-radiative return pathways (green arrow).
    • Several secondary radical reactions then follow (shown in the gray box), making it difficult to assign a quantum yield to the primary reaction.

  • The Wave Function

    • A wave function is a probability amplitude in quantum mechanics that describes the quantum state of a particle and how it behaves.
    • In quantum mechanics, a wave function is a probability amplitude describing the quantum state of a particle and how it behaves.
    • The laws of quantum mechanics (the Schrödinger equation) describe how the wave function evolves over time.
    • This figure shows some trajectories of a harmonic oscillator (a ball attached to a spring) in classical mechanics (A-B) and quantum mechanics (C-H).
    • In quantum mechanics (C-H), the ball has a wave function, which is shown with its real part in blue and its imaginary part in red.

  • Wave Equation for the Hydrogen Atom

    • The angular momentum quantum number ℓ = 0, 1, 2, ... determines the magnitude of the angular momentum.
    • This leads to a third quantum number, the principal quantum number n = 1, 2, 3, ....
    • The principal quantum number in hydrogen is related to the atom's total energy.
    • Note that the maximum value of the angular momentum quantum number is limited by the principal quantum number: it can run only up to n − 1, i.e. ℓ = 0, 1, ..., n − 1.
    • Therefore, any eigenstate of the electron in the hydrogen atom is described fully by four quantum numbers.

  • Description of the Hydrogen Atom

    • The hydrogen atom (consisting of one proton and one electron, not the diatomic form H2) has special significance in quantum mechanics and quantum field theory as a simple two-body problem physical system that has yielded many simple analytical solutions in closed-form.
    • The angular momentum quantum number ℓ = 0, 1, 2, ... determines the magnitude of the angular momentum.
    • This leads to a third quantum number, the principal quantum number n = 1, 2, 3, ....
    • The principal quantum number in hydrogen is related to the atom's total energy.
    • Note the maximum value of the angular momentum quantum number is limited by the principal quantum number: it can run only up to n − 1, i.e. ℓ = 0, 1, ..., n − 1.

  • Quantum-Mechanical View of Atoms

    • Hydrogen-1 (one proton + one electron) is the simplest form of atoms, and not surprisingly, our quantum mechanical understanding of atoms evolved with the understanding of this species.
    • Modern quantum mechanical view of hydrogen has evolved further after Schrödinger, by taking relativistic correction terms into account.
    • Quantum electrodynamics (QED), a relativistic quantum field theory describing the interaction of electrically charged particles, has successfully predicted minuscule corrections in energy levels.
    • One of the hydrogen's atomic transitions (n=2 to n=1, n: principal quantum number) has been measured to an extraordinary precision of 1 part in a hundred trillion.
    • This kind of spectroscopic precision allows physicists to refine quantum theories of atoms, by accounting for minuscule discrepancies between experimental results and theories.