On the spectral distribution of photons between planar interfaces

Using a phenomenological approach to field quantization, an expression for the Keldysh function of photons between two planar interfaces (Casimir geometry) is found for any stationary quantum state of the two bodies. The case of one interface sliding against the other is considered in detail

Universal Thermal Radiation Drag on Neutral Objects

We compute the force on a small neutral polarizable object moving at velocity $\vec v$ relative to a photon gas equilibrated at a temperature $T$ We find a drag force linear in $\vec v$. Its physical basis is identical to that in recent formulations of the dissipative component of the Casimir force. We estimate the strength of this universal Casimir drag force for different dielectric response functions and comment on its relevance in various contexts.Comment: 7 pages, 2 figure

Graphene valley polarization as a function of carrier-envelope phase in few-cycle laser pulses and its footprints in harmonic signals

We consider coherent dynamics of graphene charged carriers exposed to an intense few-cycle linearly polarized laser pulse. The results, obtained by solving the generalized semiconductor Bloch equations numerically in the Hartree-Fock approximation, taking into account many-body Coulomb interaction, demonstrate strong dependence of the valley polarization on the carrier-envelope phase (CEP), which is interpolated by the simple sinusoidal law. Then we consider harmonic generation in multi-cycle laser field by graphene preliminary exposed to an intense few-cycle laser pulse. We show that the second harmonic's intensity is a robust observable quantity that provides a gauge of CEP for pulse durations up to two optical cycles, corresponding to 40 $\mathrm{fs}$ at the wavelength of 6.2 $\mathrm{\mu m}$.Comment: 9 pages, 10 figure

Long-range correlation-induced effects at high-order harmonic generation on graphene quantum dots

This paper focuses on investigating high-order harmonic generation (HHG) in graphene quantum dots (GQDs) under intense near-infrared laser fields. To model the GQD and its interaction with the laser field, we utilize a mean-field approach. Our analysis of the HHG power spectrum reveals fine structures and a noticeable enhancement in cutoff harmonics due to the long-range correlations. We also demonstrate the essential role of Coulomb interaction in determining of harmonics intensities and cutoff position. Unlike atomic HHG, where the cutoff energy is proportional to the pump wave intensity, in GQDs the cutoff energy scales with the square root of the field strength amplitude. A detailed time-frequency analysis of the entire range of HHG spectrum is presented using a wavelet transform. The analysis reveals intricate details of the spectral and temporal fine structures of HHG, offering insights into the various HHG mechanisms in GQDs.Comment: 10 pages, 15 figure