A switchable controlled-NOT gate in a spin-chain NMR quantum computer

Abstract

A method of switching a controlled-NOT gate in a solid-stae NMR quantum computer is presented. Qubits of I=1/2 nuclear spins are placed periodically along a quantum spin chain (1-D antiferromagnet) having a singlet ground state with a finite spin gap to the lowest excited state caused by some quantum effect. Irradiation of a microwave tuned to the spin gap energy excites a packet of triplet magnons at a specific part of the chain where control and target qubits are involved. The packet switches on the Suhl-Nakamura interaction between the qubits, which serves as a controlled NOT gate. The qubit initialization is achieved by a qubit initializer consisting of semiconducting sheets attached to the spin chain, where spin polarizations created by the optical pumping method in the semiconductors are transferred to the spin chain. The scheme allows us to separate the initialization process from the computation, so that one can optimize the computation part without being restricted by the initialization scheme, which provides us with a wide selection of materials for a quantum computer.

8 pages, 5 figures

References in corpus (2)

• Experimental realization of Shor's quantum factoring algorithm using nuclear magnetic resonance
• Magnon-mediated NMR quantum gates in a 1-D antiferromagnet

Cited by in corpus (7)

• Multiple-Quantum Spin Dynamics of Entanglement
• Optical pumping NMR in the compensated semiconductor InP:Fe
• Nuclear spin qubits in a pseudo-spin quantum chain
• Dynamics of the electron-nuclear and heteronuclear polarization transfers in optically-oriented semi-insulating InP:Fe
• Surface-sensitive NMR in optically pumped semiconductors
• The controlled indirect coupling between spatially-separated qubits in antiferromagnet-based NMR quantum registers
• Antiferromagnet-based nuclear spin model of scalable quantum register with inhomogeneous magnetic field