Macroscopic quantum state in a semiconductor device

We show how nanostructuring of a metallic gate on a field-effect transistor (FET) can lead to a macroscopic, robust and voltage controlled quantum state in the electron channel of a FET. A chain of triple quantum dot molecules created by gate structure realizes a spin-half Heisenberg chain with spin-spin interactions alternating between ferromagnetic and anti-ferromagnetic. The quantum state is a semiconductor implementation of an integer spin-one antiferromagnetic Heisenberg chain with a unique correlated ground state and a finite energy gap, originally conjectured by Haldane.