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 Mn2+ 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 electron interaction with the crystal field and with the 55Mn nuclear spins.

Rabi oscillations at low and high power (up) and the calculated dressed states diagrams (bottom). The levelsplittings 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

As in the preceding years, this award contributed for the support of two graduate students, two undergraduate students and one postdoc. One undergraduate student received the Minority Undergraduate Physics Scholarship presented by the American Physical Society (APS) and the other received Honorable Mention in the Goldwater competition in 2008. The postdoc researcher has now a permanent research faculty position. Also, the group hosted two REU students and two RET teachers within the frame of the on-going outreach programs at NHMFL. The award provided the means for developing small demonstrations at outreach events. Experimental data for in-school presentations and demonstrations have been facilitated as well, within the framework of the SuperNet program at NHMFL.

Multiphoton Coherent Manipulation in Large Spin Qubits

Irinel Chiorescu (Florida State University and National High Magnetic Field Laboratory) DMR 0645408

The NHMFL Open House is a major event in Tallahassee and attracts eachyear around 4-5,000 people.

Close-up of the “Jacobs ladder” demonstration showing electrical sparksraising towards electrodes edges.