Luttinger Liquid Behavior For Photons In 1D?

This is a very intriguing theoretical idea.

Luttinger liquid is usually a property of correlated electron (fermion) systems when confined to 1D. But in this latest scheme, a proposal has been made to confined photons in 1D that could exhibit the same spin-charge separation of Luttinger liquids.

Thus the suggestion by Angelakis et al. [1] that spin-charge-separated Luttinger liquid behavior could occur for photons in a one-dimensional nonlinear medium opens the door to a host of potential new studies and applications of spin-charge separation in one dimension. The basic idea is to employ a one-dimensional nonlinear optical media with two species of atoms to create a gas of strongly interacting polaritons of two “types,” which will become the analogs of spin and charge. The proposal draws on earlier work by Chang et al. [6] in which it was shown that a regime of very strongly interacting polaritions could be achieved in a single-component one-dimensional nonlinear optical media. In the single-component case, the strongly interacting polariton system was shown to realize a Tonks gas, a strongly interacting system of bosons with contact (zero range) interactions [6], which has already been observed in cold atomic gases (as opposed to photons) of bosons [8, 9]. When the interactions in a system of bosons are very strong, particles tend to avoid the same spatial location, which mimics the Pauli exclusion principle for fermions. Of this effect, one sometimes says that the strong interactions have caused the boson system to “fermionize.” Once a one-dimensional bosonic system reaches this regime, the connection to interacting fermions becomes clear, and the mathematical descriptions of the low-energy behavior are identical.

You may obtain the paper in question at the link given above.

Now, let's see who will be the first to validate this experimentally.

Zz.