We have ionized Rydberg atoms using subpicosecond half-cycle electromagnetic pulses. The threshold electric field required to ionize a Rydberg state with effective quantum number ${\mathit{n}}^{\mathrm{*}}$ is found to scale as ${\mathit{n}}^{\mathrm{*}\mathrm{\ensuremath{-}}2}$ for states with ${\mathit{n}}^{\mathrm{*}}$ >13 in contradistinction to the ${\mathit{n}}^{\mathrm{*}\mathrm{\ensuremath{-}}4}$ threshold scaling for static field ionization and high order multiphoton ionization. This novel result is explained using a classical model.We have ionized Rydberg atoms using subpicosecond half-cycle electromagnetic pulses. The threshold electric field required to ionize a Rydberg state with effective quantum number ${\mathit{n}}^{\mathrm{*}}$ is found to scale as ${\mathit{n}}^{\mathrm{*}\mathrm{\ensuremath{-}}2}$ for states with ${\mathit{n}}^{\mathrm{*}}$>13 in contradistinction to the ${\mathit{n}}^{\mathrm{*}\mathrm{\ensuremath{-}}4}$ threshold scaling for static field ionization and high order multiphoton ionization. This novel result is explained using a classical model.

Physical Review LettersMar 1, 1993298 citations

We have ionized Rydberg atoms using subpicosecond half-cycle electromagnetic pulses. The threshold electric field required to ionize a Rydberg state with effective quantum number

{\mathit{n}}^{\mathrm{*}}

is found to scale as ${\mathit{n}}^{\mathrm{*}\mathrm{\ensuremath{-}}2}$ for states with

{\mathit{n}}^{\mathrm{*}}

>13 in contradistinction to the ${\mathit{n}}^{\mathrm{*}\mathrm{\ensuremath{-}}4}$ threshold scaling for static field ionization and high order multiphoton ionization. This novel result is explained using a classical model.