Seminarium Fizyki Materii Skondensowanej

Open problems in general relativity have motivated the search for analogue gravitational systems in condensed matter implementations. In one such system, a 1D tight-binding model with position-dependent hopping, the possibility of realizing an analogue gravitational horizon has recently been demonstrated. Here, we introduce the concept of emergent temperature, inspired by Unruh radiation, and show that it arises naturally in tight-binding lattice models featuring a horizon. Despite finding many similarities between the emergent lattice temperature and the gravitational Unruh temperature, we show that the nature of the thermal spectrum in the lattice theory is radically different from that in the continuum limit. Additionally, we provide a detailed analysis of outgoing radiation delineating the conditions under which the horizon behaves purely as a thermal source.