IMR: Development of a Transient Spectrometer for Education and Research into Quantum Coherence in Molecular Nanomagnets

University Of Florida, Gainesville FL

Investigators

Abstract

This project will advance existing spectroscopic capabilities at the University of Florida (UF) and the National High Magnetic Field Laboratory (NHMFL) through the development of a unique broadband transient spectrometer which will be used for interdisciplinary collaborative research and student training. Experiments will focus on single-molecule magnets (SMMs), which represent a molecular approach to nanoscale and sub-nanoscale science, with potential applications in quantum computational devices. Very little is known about the coupling of such a nanomagnet to its environment, and how this coupling affects the coherence of quantum superposition states. Thus, we will develop a spectrometer capable of addressing questions relating to the quantum dynamics of molecule-based nanomagnets. A unique instrument will be developed, enabling: broadband continuous-wave frequency coverage (8 to 500 GHz); pump/probe and time domain capabilities (up to 300 GHz) with sub-microsecond resolution; and precise control over the DC magnetic field orientation. Experiments will include: rapid passage and transient EPR studies of magnetic quantum tunneling in SMMs; hole-burning and double resonance (ELDOR) investigations of quantum dephasing mechanisms in nanomagnets; and, ultimately, coherent control of the quantum spin states of SMMs. The new instrumentation will have important uses beyond the scope of the investigations described in this proposal, e.g. for high-resolution high-frequency EPR with applications in chemistry and even biology. The PI will collaborate with researchers at the NHMFL with the aim of developing a similar instrument for users of this facility. The PI is also involved in a range of outreach/education activities (related to an NSF CAREER award) which will benefit immensely from this project. %%% This project will build upon existing experimental capabilities available to researchers at the University of Florida (UF) and the National High Magnetic Field Laboratory (NHMFL) through the development of a new instrument which will be used for interdisciplinary collaborative research and student training. Experiments will focus on single-molecule magnets (SMMs), which represent a molecular approach to nanoscale science, with potential applications in quantum computing. The major hurdle in the development of a quantum computer is the so-called "decoherence" problem, whereby "quantum information" is irreversibly lost to the environment due to the simple fact that it is both impractical and impossible to completely isolate a quantum device from its surroundings. This decoherence can be studied using time-resolved magnetic or optical measurement techniques. Studies of SMMs will require capabilities covering a wide portion of the microwave frequency range, and with time resolution on the order of a fraction of a microsecond. Furthermore, an ability to control the quantum states of SMMs with a strong magnetic field is also needed. This project will address these pressing needs, resulting in a unique experimental instrument. The PI will collaborate with researchers at the NHMFL with the aim of developing similar capabilities for users of this national facility. In particular, the new instrumentation will have important uses beyond the research into the quantum properties of SMMs, e.g. for high-frequency electron paramagnetic resonance (EPR) studies of problems in chemistry and even biology. Finally, the PI is involved in a range of outreach/education activities (related to an NSF CAREER award) which will benefit immensely from the development of the new instrument.