Nuclear-spin polaron formation: Anisotropy effects and quantum phase transition

Continuous time crystal in an electron-nuclear spin system: stability and melting of periodic auto-oscillations

“…The first one is the spontaneous phase transition to a magnetically ordered, antiferromagnetic nuclear state canceling the fluctuations in the nuclear spin ensemble. This state is expected to develop by deep cooling of the nuclei to temperatures in the order of 10 −7 K [12][13][14][15][16][17] , Recently, advanced cooling protocols allowed achieving record nuclear spin temperatures of 5 × 10 −7 K in GaAs 18 , which, however, was not yet sufficient for the phase transition.…”