Like I mention in the paper, the largest object for which we’ve done this so far (at least that I’m aware of) is Carbon 60 atoms which, while impressive, are far from “macroscopic.” Preventing a superposition from decohering is really, really difficult—it’s what makes building a quantum computer so hard. That being said, there are some wacky macroscopic objects that do sometimes need to be treated as quantum systems, like neutron stars (as I mention in the paper) or black holes (though we still don’t fully understand black holes from a quantum perspective).
Like I mention in the paper, the largest object for which we’ve done this so far (at least that I’m aware of) is Carbon 60 atoms which, while impressive, are far from “macroscopic.” Preventing a superposition from decohering is really, really difficult—it’s what makes building a quantum computer so hard. That being said, there are some wacky macroscopic objects that do sometimes need to be treated as quantum systems, like neutron stars (as I mention in the paper) or black holes (though we still don’t fully understand black holes from a quantum perspective).
Ah, yeah, neutron stars do feel like a good example. And I do just recall you mentioning them.