Single-nucleus quantum beats excited by synchrotron radiation

Abstract

We have observed single-nucleus quantum beats in the incoherent scattering of synchrotron radiation by the 14.4 keV transition of 57 Fe. The 20 ns beat period characteristic of the nuclear excited-state splitting was clearly seen when enriched metallic samples were excited at the nuclear resonance energy or far from the resonance energy (i.e. accompanied by phonon excitation). The phase of the beat pattern is seen to change with the scattering angle in a manner consistent with the angular-momentum change of the (M1) transition.

Hyperfine interactions inN61iwith synchrotron-radiation-based perturbed angular correlations

“…The first study of the magnetic quantum beats in the incoherent-scattering channel has been performed with iron. 6 Recently, the application of SRPAC to study quadrupole interactions and relaxation in soft condensed matter has been demonstrated for the case of iron containing ferrocene molecules inserted into a glass former 7 and for the case of tributyltin fluoride polymer 11 containing the Mössbauer isotope 119 Sn.…”

Synchrotron-radiation-based perturbed angular correlations used in the investigation of rotational dynamics in soft matter

“…In order to estimate the influence of this contribution we measured the SRPAC signal at 100 K off resonance, as performed in Ref. 25. Here we moved the bandwidth of the monochromator 20 meV above the nuclear resonance, so that nuclear scattering can occur only with creation of phonons.…”

“…Besides timeintegral applications, [22][23][24] first time-differential studies have been performed, where typical magnetic quantum beats have been demonstrated in single-nucleus scattering by pure iron. 25 Recently, spatially incoherent scattering was applied to study site-specific phonon densities of states. 26 In the present study we have applied SRPAC for the first time to investigate hyperfine interactions and dynamics of Mössbauer atoms in the case of f LM ϳ 0.…”

Condensed Matter Physics Using Nuclear Resonant Scattering

“…For materials such as these, another option is to utilize the spatially incoherent channel of nuclear resonant scattering. [29][30][31] In contrast to coherent nuclear resonant forward scattering and Bragg scattering, which involve the collective coherent excitation and decay of many nuclei, the incoherent scattering from single nuclei exhibits quantum beat patterns that reflect only excited-state splitting. Although the -rays released during incoherent processes are emitted equally in all directions, the phase of the quantum beat patterns is dependent on the angle between the incident radiation and the emitted radiation.…”