Project 3: Entanglement in Mesospin Systems
3.2. Magnetic Properties of Mesospin Systems
A key aspect of our research is to significantly raise the critical temperature below which entanglement can be produced and exploited for quantum computing. One way of realizing this goal is to use mesocopic magnets. In mesospin systems, interatomic exchange coupling and magnetic anisotropy enable one to enhance the temperature below which quantum effects can be exploited. Our proposed structures will include molecules and linear chains in which blocks of S > ½ spins will be coupled antiferromagnetically. Systems under investigation are organic radicals (nitroxides), metal ions with half-filled d or f shells MnII and GdIII, and magnetic nanodots.
The experimental and theoretical investigation of the structures focusses on two aspects of importance for entanglement and quantum computation: on the interatomic exchange and on the magnetocrystalline anisotropy. Because antiferromagnetic exchange couplings, J/k, for nitroxide-MnII and nitroxide-GdIII pairs are on the order of 300 K and 2 K, respectively, a wide range of antiferromagnetic J/k will be explored. An analogous range of J/k for nitroxide-nitroxide pairs is even wider, including both ferromagnetic and antiferromagnetic couplings: |J/k| ranging from several mK to about room temperature.