  In the last two decades, considerable advances have been made in the
investigation of nano-photonics in photonic crystals. Previous theoretical
investigations of photon dynamics were carried out at zero temperature. Here,
we investigate micro/nano cavity photonics in photonic crystals at finite
temperature. Due to photonic-band-gap-induced non-Markovian dynamics, we
discover that cavity photons in photonic crystals do not obey the standard
Bose-Einstein statistical distribution. Within the photonic band gap and in the
vicinity of the band edge, cavity photons combine nontrivial quantum
dissipation with thermal fluctuations to form photon states that can memorize
the initial cavity state information. As a result, Bose-Einstein distribution
is completely broken down in these regimes, even if the thermal energy is
larger than the photonic band gap.
