Multiphoton Coherent Manipulation in Large Spin Qubits Irinel Chiorescu (Florida State University and National High Magnetic Field Laboratory) DMR 0645408 Manipulation of quantum information allows certain algorithms to be performed at unparalleled speeds. Spin-based qubits have well known behavior under photon driving and can be potentially operated up to room temperature. We have used large spin Mn 2+ ions (S=5/2) to realize a six level system that can be operated by means of single and multi-photon coherent Rabi oscillations. The effect of a small anisotropy on spin dynamics was analyzed and ways to control the levels non-harmonicity were found. In contrast to the two-level qubits, multi-photon Rabi oscillations in large spins qubits are enhanced by the intermediate levels in between the direct coupled levels. Decoherence effects are strongly reduced by the quasi-isotropic Rabi oscillations at low and high power (up) and the calculated dressed states diagrams (bottom). The level splittings give the Rabi frequency corresponding to each multi-photon coherent qubit nutation. S. Bertaina, L. Chen, N. Groll, J. van Tol, N.S. Dalal, I. Chiorescu: “Multiphoton coherent manipulation in large-spin qubits”; submitted