3 papers
physics.optics2026
Quantum Photonic Time Crystals: From Temporal Boundaries to Floquet Light-Matter Interactions
Younsung Kim, Kyungmin Lee, Kun Woo Kim +1
Photonic time crystals (PTCs) are temporally periodic media whose Floquet spectra can exhibit momentum gaps, parametric amplification, and effective non-Hermitian descriptions, mak…
physics.optics2026
Energy Transport Velocity in Photonic Time Crystals
Kyungmin Lee, Younsung Kim, Kun Woo Kim +1
Steep or near-vertical Floquet dispersion in photonic time crystals (PTCs) is often read as fast, even apparently superluminal, transport. Here, we demonstrate that this anomaly ar…
physics.optics2026
Classical Petermann Factor as a Measure of Quantum Squeezing in Photonic Time Crystals
Younsung Kim, Kyungmin Lee, Changhun Oh +3
Photonic time crystals realize a continuum of momentum-resolved SU(1,1) parametric amplifiers. We show that a classical quantity, the Petermann factor of the effective Floquet Bogo…