Generating entanglement and squeezed states of nuclear spins in quantum dots

Abstract

We present a scheme for achieving coherent spin squeezing of nuclear spin states in semiconductor
quantum dots. The nuclear polarization dependence of the electron spin resonance generates a unitary
evolution that drives nuclear spins into a collective entangled state. The polarization dependence of the
resonance generates an area-preserving, twisting dynamics that squeezes and stretches the nuclear spin
Wigner distribution without the need for nuclear spin flips. Our estimates of squeezing times indicate that
the entanglement threshold can be reached in current experiments.