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Few-body spin couplings and their implications for universal quantum computation

Ryan Woodworth·Ari Mizel·Daniel A. Lidar
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Abstract

Electron spins in semiconductor quantum dots are promising candidates for the experimental realization of solid-state qubits. We analyze the dynamics of a system of three qubits arranged in a linear geometry and a system of four qubits arranged in a square geometry. Calculations are performed for several quantum dot confining potentials. In the three-qubit case, three-body effects are identified that have an important quantitative influence upon quantum computation. In the four-qubit case, the full Hamiltonian is found to include both three-body and four-body interactions that significantly influence the dynamics in physically relevant parameter regimes. We consider the implications of these results for the encoded universality paradigm applied to the four-electron qubit code; in particular, we consider what is required to circumvent the four-body effects in an encoded system (four spins per encoded qubit) by the appropriate tuning of experimental parameters.

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Ryan Woodworth, Ari Mizel, Daniel A. Lidar. 2005-06-18. Few-body spin couplings and their implications for universal quantum computation. https://doi.org/10.1088/0953-8984%2F18%2F21%2Fs02

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