Abstract: A molecular-spin qubit includes a molecular color center having a ground state and an excited state. The ground state has non-zero spin with at least first and second sublevels. The molecular-spin qubit also includes a host matrix that is non-isostructural with the molecular color center. The molecular color center is diluted in the host matrix. An optical transition between the ground and excited states lies in the optical region of the electromagnetic spectrum. A spin transition between the first and second sublevels lies in the microwave or millimeter-wave regions of the electromagnetic spectrum. Each of the first and second sublevels is first-order insensitive to magnetic fields near zero magnetic. The molecular color center and host matrix may each be formed from strong-field ligands bound to a metal-atom center. One example of the molecular-spin qubit is Cr(IV)(o-toyl)4 diluted in a host matrix of Sn(IV)(4-fluoro-2-methylphenyl)4.

Abstract: Methods and devices are disclosed for implementing quantum information processing based on electron spins in semiconductor and transition metal compositions. The transition metal electron orbitals split under semiconductor crystal field. The electron ground states are used as qubits. The transitions between the ground states involve electron spin flip. The semiconductor and transition metal compositions may be further included in optical cavities to facilitate quantum information processing. Quantum logic operations may be performed using single color or two color coherent resonant optical excitations via an excited electron state.

Abstract: Methods and devices are disclosed for implementing quantum information processing based on electron spins in semiconductor and transition metal compositions. The transition metal electron orbitals split under semiconductor crystal field. The electron ground states are used as qubits. The transitions between the ground states involve electron spin flip. The semiconductor and transition metal compositions may be further included in optical cavities to facilitate quantum information processing. Quantum logic operations may be performed using single color or two color coherent resonant optical excitations via an excited electron state.

Abstract: Methods and devices are disclosed for implementing quantum information processing based on electron spins in semiconductor and transition metal compositions. The transition metal electron orbitals split under semiconductor crystal field. The electron ground states are used as qubits. The transitions between the ground states involve electron spin flip. The semiconductor and transition metal compositions may be further included in optical cavities to facilitate quantum information processing. Quantum logic operations may be performed using single color or two color coherent resonant optical excitations via an excited electron state.

Abstract: Methods and devices are disclosed for implementing quantum information processing based on electron spins in semiconductor and transition metal compositions. The transition metal electron orbitals split under semiconductor crystal field. The electron ground states are used as qubits. The transitions between the ground states involve electron spin flip. The semiconductor and transition metal compositions may be further included in optical cavities to facilitate quantum information processing. Quantum logic operations may be performed using single color or two color coherent resonant optical excitations via an excited electron state.

Abstract: A bipolar spin transistor is provided. In one embodiment of the present invention, the bipolar spin transistor includes a first semiconductor region having a first conductivity type, a second semiconductor region having a second conductivity type that is different from the first conductivity type and also having a spin polarization, and a third semiconductor region having a conductivity type that is the same conductivity type of the first semiconductor region. The first semiconductor region and the second semiconductor region are adjacent to each other so as to form a first charge depletion layer therebetween, the first charge depletion layer having a first side facing the first semiconductor region and an opposing second side facing the second semiconductor region.