Symmetry and Quantum Interference in the Attosecond Domain

In this review, we examine the interplay of symmetry and quantum interference in the attosecond domain primarily through one- and two-electron photoelectron momentum distributions. Using our own work, we discuss how tailored laser fields provide control over dynamical symmetries, and how quantum-orbit methods make it possible to connect the resulting momentum-space structures to specific ionisation, propagation, and rescattering pathways. Particular emphasis is placed on ultrafast photoelectron holography and nonsequential double ionisation through recollision excitation with subsequent ionisation, where several distinct forms of quantum interference can be identified and manipulated. We also discuss how target properties, including the binding potential, orbital symmetry and parity, modify this mapping. Finally, we consider emerging opportunities offered by non-classical states of light, for which photon statistics and quantum fluctuations provide additional degrees of freedom for controlling symmetry and strong-field electron dynamics.