



@article {1338,
	title = {A chemical potential for light},
	journal = {Physical Review B},
	volume = {92},
	year = {2015},
	month = {2014/05/22},
	pages = {174305},
	abstract = {Photons are not conserved in interactions with other matter. Consequently, when understanding the equation of state and thermodynamics of photons, while we have a concept of temperature for energy conservation, there is no equivalent chemical potential for particle number conservation. However, the notion of a chemical potential is crucial in understanding a wide variety of single- and many-body effects, from transport in conductors and semi-conductors to phase transitions in electronic and atomic systems. Here we show how a direct modification of the system-bath coupling via parametric oscillation creates an effective chemical potential for photons even in the thermodynamic limit. Specific implementations, using circuit-QED or optomechanics, are feasible using current technologies, and we show a detailed example demonstrating the emergence of Mott Insulator-superfluid transition in a lattice of nonlinear oscillators. Our approach paves the way for quantum simulation, quantum sources and even electron-like circuits with light.
},
	doi = {10.1103/PhysRevB.92.174305},
	url = {http://arxiv.org/abs/1405.5821v2},
	author = {M. Hafezi and P. Adhikari and J. M. Taylor}
}
