For the confused (like I was):
"They did not create an entity that actually possesses "negative mass". They created configurations of energy states within a material that CAN BE CHARACTERIZED as a quasiparticle; there is no requirement that we think of it as a particle-like entity, it's just convenient from certain respects. In turn that quasiparticle behaves, in at least some respects, as if it were a particle with "negative mass", although from the sound of things, "negative inertia" would be a more accurate description of the phenomena they actually observed." - DarkLordKelvin
Re: Alcubierre drive
It needs imaginary mass, not just negative mass.
Edit: I confused the drive's requirements with tachyons.
Given the need for negative mass, I ask the obligatory question as to whether or not this is even the smallest step towards the Alcubierre drive?
Original press release: http://www.rochester.edu/newscenter/vamivakas-microcavity-ne...
Wait, they made roton quasiparticles, not actual exotic matter, right?
Any theoretical bearing on the Alcubierre Drive or is this a different domain-specific concept of negative mass?