The low microwave energies achievable in this experiment (10-30 GHz) will enable studies of a variety of SMMs without decimating the role of the intrinsic molecular anisotropy by the application of large magnetic fields [the figure above shows a mononuclear (left) and a polynuclear (right) SMM and their respective anisotropy barriers]. This is particularly important for Rabi oscillations induced by pulsed electromagnetic radiation. When a large magnetic field imposes the quantization axis (Zeeman energy), induced transitions occur between spin levels that are eigenstates of the Hamiltonian. In this case, the spin quantum dynamics can be calculated analytically and correspond to simple Rabi oscillations where the system alternates between the two states involved. However, when the anisotropy barrier is comparable to the Zeeman energy, Rabi transitions may involve states resulting from symmetric and antisymmetric superpositions of eigenstates of the Hamiltonian. In this case, the Rabi oscillations are not well defined and the quantum nature of the commutation between the spin operators leads to complex dynamics where the magnetic state of the molecule may develop excited precessional states. This exciting characteristic of the light-matter interaction in magnetic systems is unique for SMMs.
Recent Publications on this topic:
R. Cebulka, and E. del Barco
“Sub-Kelvin (100mK) Time Resolved EPR Spectroscopy for Studies of Quantum Dynamics of Low-Dimensional Spin Systems at Low Frequencies and Magnetic Fields”
Rev. Sci. Instrum. 90, 085106 (2019)
Collaborators:
Physics:
Philip Stamp and Igor Tupitsyn (UBC, Vancouver, Canada)
Seiji Miyashita (UT, Tokio, Japan)
Chemistry:
Eugenio Coronado (UV, Valencia, Spain)
Guillem Aromi (UB, Barcelona, Spain)
Selvan Demir (Michigan, US)