Supersolid in thermal phase diagram of symmetric electron-hole semiconductor bilayer

One of the most fascinating phases of matter is the supersolid phase. The supersolid phase of matter juxtaposes two a priori conflicting physical properties: a long range ordered structure phase and non vanishing superfluid transport properties [1]. Recently, it has been the focus of intense research as there have been experimental reports which claim to observe a supersolid phase in ⁴He[2] through the observation of enhancements in the resonant period of their torsional oscillator as the system is cooled. However, the large superfluid mass fraction[2] observed appears to favor a solid amorphous structure, a superglass phase, rather than the desired supersolid phase[3], [4].