Subcycle pulse control of holographic and nonholographic electron interferences

We investigate the influence of subcycle laser pulses on holographic and nonholographic intracycle interferences by analyzing the photoelectron momentum distributions of helium using time-dependent Schrödinger equation simulations supported by classical-trajectory calculations. The results show that the forward-scattering holographic (FSH), backward-scattering holographic (BSH), and time double-slit (TDS) interference structures are found to be highly sensitive to the pulse duration, carrier-envelope phase (CEP), and temporal envelope in the subcycle regime. Subcycle pulses with CEP values of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:msup> <a:mn>0</a:mn> <a:mo>∘</a:mo> </a:msup> </a:math> and <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:msup> <b:mn>90</b:mn> <b:mo>∘</b:mo> </b:msup> </b:math> selectively enhance or suppress distinct features, isolating holographic patterns and enhancing BSH fringes. Classical analysis reveals that the intrinsic chirp inherent to subcycle fields shortens the recollision time for scattering trajectories, thereby increasing the fringe spacing in FSH and BSH patterns, while simultaneously enlarging the above-threshold ionization peak spacing associated with TDS interference. Pulse envelope variations, even at fixed FWHM duration, further reshape the fringe spacings by modifying the instantaneous frequency and vector potential slope near ionization times. These results demonstrate that subcycle pulses enable precise temporal control of holographic interference, offering opportunities for probing and manipulating attosecond electron dynamics.