In a new study published in Nature Physics, researchers have demonstrated that quantum light, particularly bright squeezed vacuum (BSV), can drive strong-field photoemission at metal needle tips.

Attosecond science—the study of electron behavior on timescales of 10⁻¹⁸ seconds—has traditionally relied on intense laser pulses that correspond to “coherent states” of light. They function as classical electromagnetic waves with predictable, oscillating electric fields that push electrons to high energies.

When electrons rescatter from surfaces under this intense illumination, they produce characteristic signatures: a plateau in their energy spectrum followed by a sharp cut-off. These features have become central to probing matter with attosecond precision.