High-order above-threshold ionization by squeezed coherent light

Squeezed coherent quantum light is described by the complex squeeze parameter <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mrow> <a:mi>ζ</a:mi> <a:mo>=</a:mo> <a:mi>s</a:mi> <a:msup> <a:mi>e</a:mi> <a:mrow> <a:mi>i</a:mi> <a:mi>ϑ</a:mi> </a:mrow> </a:msup> </a:mrow> </a:math> and the coherent-state displacement parameter <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:mrow> <b:mi>β</b:mi> <b:mo>=</b:mo> <b:mrow> <b:mo>|</b:mo> <b:mi>β</b:mi> <b:mo>|</b:mo> </b:mrow> <b:msup> <b:mi>e</b:mi> <b:mrow> <b:mi>i</b:mi> <b:msub> <b:mi>ϕ</b:mi> <b:mi>β</b:mi> </b:msub> </b:mrow> </b:msup> </b:mrow> </b:math> . Our study of strong-field ionization [D. Habibović and D. B. Milošević, ], which focused on bright squeezed vacuum quantum light with <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"> <c:mrow> <c:mi>β</c:mi> <c:mo>=</c:mo> <c:mn>0</c:mn> </c:mrow> </c:math> and <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mrow> <d:mi>s</d:mi> <d:mo>≫</d:mo> <d:mn>1</d:mn> </d:mrow> </d:math> , is extended to ionization by squeezed coherent light. It is shown that the amplitudes <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"> <e:mi>s</e:mi> </e:math> and <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"> <f:mrow> <f:mo>|</f:mo> <f:mi>β</f:mi> <f:mo>|</f:mo> </f:mrow> </f:math> strongly influence the ionization process, whereas phases <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"> <g:mi>ϑ</g:mi> </g:math> and <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"> <h:msub> <h:mi>ϕ</h:mi> <h:mi>β</h:mi> </h:msub> </h:math> play a less significant role. The present work provides a unified treatment of coherent, squeezed vacuum, and squeezed coherent light within a single theoretical framework. The quantum nature of the driving field is incorporated by averaging the strong-field ionization probability over the Husimi-Kano phase-space distribution. Using neon as a representative target, we analyze how the parameters characterizing squeezed coherent light modify photoelectron spectra and intensity-dependent enhancements. We show that nonclassical photon statistics can lead to a pronounced steepening of the rescattering plateau and, at low mean intensities, to an effective suppression of the nominal high-energy cutoff. These effects originate from the reduced weight of high-intensity field components inherent to squeezed states and have no analog in strong-field ionization driven by a coherent light. Our results highlight the potential for quantum-statistical control of strong-field ionization and provide a foundation for exploring laser-matter interactions driven by quantum light.