We theoretically study an impulsively excited quantum bouncer (QB)-a particle bouncing off a surface in the presence of gravity. A pair of time-delayed pulsed excitations is shown to induce a wave-packet echo effect-a partial rephasing of the QB wave function appearing at twice the delay between pulses. In addition, an appropriately chosen observable [here, the population of the ground gravitational quantum state (GQS)] recorded as a function of the delay is shown to contain the transition frequencies between the GQSs, their populations, and partial phase information about the wave-packet quantum amplitudes. The wave-packet echo effect is a promising candidate method for precision studies of GQSs of ultracold neutrons, atoms, and antiatoms confined in closed gravitational traps.
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http://dx.doi.org/10.1103/PhysRevLett.126.170403 | DOI Listing |
Phys Chem Chem Phys
January 2025
Abteilung für Molekulare Physikalische Chemie, Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany.
The binding of carbon dioxide to a transition metal is a complex phenomenon that involves a major redistribution of electron density between the metal center and the triatomic ligand. The chemical reduction of the ligand reveals itself unambiguously by an angular distortion of the CO-molecule as a result of the occupation of an anti-bonding π-orbital and a shift of its antisymmetric stretching vibration, ν, to lower wavenumbers. Here, we generate a carbon dioxide complex of the heavier group-10 metal, platinum, by ultrafast electronic excitation and cleavage of CO from the photolabile oxalate precursor, oxaliplatin, and monitored the ensuing primary dynamics with ultrafast mid-infrared spectroscopy.
View Article and Find Full Text PDFSensors (Basel)
December 2024
College of Automation & College of Artificial Intelligence, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
The design and study of pulsed eddy current sensors for detecting surface defects in small-diameter rods are highly significant. Accurate detection and identification of surface defects in small-diameter rods may be attained by the ongoing optimization of sensor design and enhancement of detection technologies. This article presents the construction of a non-coaxial differential eddy current sensor (Tx-Rx sensor) and examines the detection of surface defects in a small diameter bar.
View Article and Find Full Text PDFPsychophysiology
January 2025
Department of Psychology, Hangzhou Normal University, Hangzhou, Zhejiang, China.
The aperiodic exponent of the power spectrum of signals in several neuroimaging modalities has been found to be related to the excitation/inhibition balance of the neural system. Leveraging the rich temporal dynamics of resting-state pupil fluctuations, the present study investigated the association between the aperiodic exponent of pupil fluctuations and the neural excitation/inhibition balance in attentional processing. In separate phases, we recorded participants' pupil size during resting state and assessed their attentional orienting using the Posner cueing tasks with different cue validities (i.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Radboud University Nijmegen, Institute for Molecules and Materials, 6525 AJ, Nijmegen, The Netherlands.
Resonant pumping of the electronic f-f transitions in the orbital multiplet of dysprosium ions (Dy^{3+}) in a complex perovskite DyFeO_{3} is shown to impulsively launch THz lattice dynamics corresponding to the B_{2g} phonon mode, which is dominanted by the motion of Dy^{3+} ions. The findings, supported by symmetry analysis and density-functional theory calculations, not only provide a novel route for highly selective excitation of the rare-earth crystal lattices but also establish important relationships between the symmetry of the electronic and lattice excitations in complex oxides.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Center for Alloy Innovation and Design, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
Light-matter interaction is a long-standing promising topic that can be dated back to a few centuries ago and has witnessed the long-term debate between the particle and wave nature of light. In modern condensed matter physics and materials science, light usually serves as a detection tool to effectively characterize the physical and chemical features of samples. The light modulation on intrinsic properties of materials, such as atomic geometries, electronic bands, and magnetic behaviors, is more intriguing for information control and storage.
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