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Electromagnon Excitation In Cupric Oxide Measured By Fabry-Pérot Enhanced Terahertz Mueller Matrix Ellipsometry, Sean Knight, Dharmalingam Prabhakaran, Christian Binek, Mathias Schubert
Electromagnon Excitation In Cupric Oxide Measured By Fabry-Pérot Enhanced Terahertz Mueller Matrix Ellipsometry, Sean Knight, Dharmalingam Prabhakaran, Christian Binek, Mathias Schubert
Christian Binek Publications
Here we present the use of Fabry-Pérot enhanced terahertz (THz) Mueller matrix ellipsometry to measure an electromagnon excitation in monoclinic cupric oxide (CuO). As a magnetically induced ferroelectric multiferroic, CuO exhibits coupling between electric and magnetic order. This gives rise to special quasiparticle excitations at THz frequencies called electromagnons. In order to measure the electromagnons in CuO, we exploit single-crystal CuO as a THz Fabry-Pérot cavity to resonantly enhance the excitation’s signature. This enhancement technique enables the complex index of refraction to be extracted. We observe a peak in the absorption coefficient near 0.705 THz and 215 K, which corresponds …
Exact Analytic Relation Between Quantum Defects And Scattering Phases With Applications To Green’S Functions In Quantum Defect Theory, V. E. Chernov, N. L. Manakov, Anthony F. Starace
Exact Analytic Relation Between Quantum Defects And Scattering Phases With Applications To Green’S Functions In Quantum Defect Theory, V. E. Chernov, N. L. Manakov, Anthony F. Starace
Anthony F. Starace Publications
The relation between the quantum defects, μλ, and scattering phases, δλ, in the single-channel Quantum Defect Theory (QDT) is discussed with an emphasis on their analyticity properties for both integer and noninteger values of the orbital angular momentum parameter λ. To derive an accurate relation between μλ and δλ for asymptotically-Coulomb potentials, the QDT is formally developed for the Whittaker equation in its general form “perturbed” by an additional short-range potential. The derived relations demonstrate that μλ is a complex function for above-threshold energies, which is analogous to the fact that δ …