Richard E. Eykholt

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This Letter reports experimental results on the three-wave interactions of backward volume spin waves in a magnetic film and the excitation of chaotic waves through such interactions in a magnetic film-based active feedback ring. The three-wave interactions manifest themselves in the power saturation responses of spin waves, and the chaotic excitation(More)
We investigate rhythmic finger tapping in both the presence and the absence of a metronome. We examine both the time intervals between taps and the time lags between the stimulus tones from the metronome and the response taps by the subject. We analyze the correlations in these data sets, and we search for evidence of deterministic chaos, as opposed to(More)
The amplification of supercritical waves in steep channels is examined analytically using a one-dimensional dynamic solution of the Saint-Venant equations. Existing methods were modified to describe the amplification of surface waves over a normalized channel length rather than over a single wavelength. The results are strikingly different, and a(More)
This Letter reports the first experimental demonstration of chaotic excitations through modulational instability for waves with a repulsive nonlinearity. The experiments were carried out for surface spin waves in a magnetic thin film strip in an active feedback ring configuration. At a low ring gain level, one observes the self-generation of one eigenmode.(More)
Chaotic spin-wave solitons in magnetic film active feedback rings were observed for the first time. At some ring gain level, one observes the self-generation of a single spin-wave soliton pulse in the ring. When the pulse circulates in the ring, its amplitude varies chaotically with time. Numerical simulations based on a gain-loss nonlinear Schrödinger(More)
We examine the dynamic and geometric phases of the electron in quantum mechanics using the space-time algebra formalism. In doing so we are able to relate the β parameter in Hestenes’ theory to these phases. We also comment on some of Hestenes’ previous work regarding the phases. keywords: Dirac spinor, geometric algebra, geometric phase PACS: 03.65.Pm,(More)
We use geometric algebra to study the phases of Pauli and Dirac spinors. It is shown that the dynamic phase is the intrinsic phase of a Pauli spinor. Using this insight, we then define the geometric and dynamic phases of a Dirac spinor. These formulas can then be used in Hestenes’ zitterbewegung theory of the electron keywords: Dirac spinor, geometric(More)
This paper reports on experimental data on the controlled tuning of chaotic surface spin waves in a magnetic-film active feedback ring. The chaotic behavior of these waves arises through three-wave nonlinear interactions. With a change in the ring gain, two chaotic regimes were observed. One corresponds to the situation where only one ring eigenmode was(More)