KnowraStark effectStark effectThe shift or splitting of atomic or molecular energy levels and spectral lines caused by an external electric field.BriefConnectQuantum-mechanical perturbation theory: An approximation method that calculates how small changes to a system alter its quantum states and energies. It predicts energy shifts when the applied field is weak.Linear Stark effect: An energy shift proportional to electric-field strength, arising when a state has a nonzero dipole interaction within its relevant subspace. Hydrogen's degenerate states exhibit this first-order response.Stark spectroscopy: Spectroscopy that applies an electric field to measure or interpret field-dependent energy levels and transitions. It extracts dipole moments and polarizabilities from observed shifts.Johannes Stark: A German physicist who discovered the electric-field splitting of spectral lines in 1913. His observation gave the effect its name and earned him the 1919 Nobel Prize in Physics.Zeeman effect: The shift or splitting of spectral lines caused by a magnetic field. It is the magnetic-field counterpart to the Stark effect.Electric dipole moment: A measure of the separation of positive and negative charge in a system. Its interaction with the field produces the leading shift in many Stark patterns.Quadratic Stark effect: An energy shift proportional to the square of electric-field strength at weak fields. Nondegenerate states commonly shift this way through induced polarization.Rydberg atom: An atom excited to a state with an electron at a very high principal quantum number. Its large polarizability makes Stark tuning and field sensing highly sensitive.Pieter Zeeman: A Dutch physicist whose discovery showed that a magnetic field splits spectral lines. The Zeeman effect supplied the magnetic counterpart that clarified field-induced spectral splitting.Fine structure: Small atomic energy-level splittings caused mainly by relativistic and spin-dependent interactions. It splits levels even without an externally applied electric field.Show all 26Linked from 14 pagesAtomic physicsBroader topic: It shows how external electric fields perturb atomic energy levels.Hydrogen spectral seriesRelated: Changes to hydrogen lines can diagnose electric fields and plasma density.Sommerfeld modelRelated: Its complex patterns exposed limits in early orbit-based quantum models.ErbiumRelated: Local electric fields in glass split erbium energy levels and shape its emission spectrum.Degenerate energy levelsRelated: An electric field can distinguish states that had equal energies.Dipole approximationRelated: Its common perturbative treatment couples the field to the system's electric dipole moment.Atomic and molecular processes in external fieldsRelated: It is the characteristic spectral response to an applied electric field.Closed-orbit theoryRelated: The field deforms the Coulomb dynamics and creates the trajectories analyzed by the theory.Show all 14