  In a recent Letter, Gopalakrishnan, Martin, and Demler [Phys. Rev. Lett. 111
(2013) 185304] show that quasi-two-dimensional dipolar Bose gases, subject to a
Rashba spin-orbit coupling, exhibit a variety of spatially ordered, or
crystalline, ground states, including a pentagonal quasicrystal. Indeed, as the
authors say, realizing quasicrystalline condensates would provide new ways to
explore the physics of quasicrystals, and in particular to study the quantum
dynamics of their unique collective phason modes. Yet, the authors conclude
that "there are typically additional phasons in quantum-mechanical
quasicrystals, when compared with their classical equivalents." In this Comment
I review the notion of phason modes in quasicrystals, and explain why their
number does not depend on whether they are classical or quantum.
