Observation of spontaneous ferromagnetism in a two-dimensional electron system
Observation of spontaneous ferromagnetism in a two-dimensional electron system
What are the ground states of an interacting, low-density electron system? In the absence of disorder, it has long been expected that as the electron density is lowered, the exchange energy gained by aligning the electron spins should exceed the enhancement in the kinetic (Fermi) energy, leading to a (Bloch) …