SKYRMION LIQUID-PHASE OF THE QUANTUM FERROMAGNET IN 2 DIMENSIONS

The two-dimensional quantum ferromagnet filled with a liquid of skyrmi ons is studied theoretically in the context of the quantum Hall effect near electronic filling factor nu = 1. A crossover between the classi cal ferromagnetic phase at nu = 1 and a classical paramagnetic phase a t nu not equal 1 is obtained, which is consistent with recent Knight-s hift measurements. A new collective mode associated with the skyrmion liquid that is of the cyclotron type is also identified.