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Abstract The nature of the 3‐s ultralow frequency (ULF) wave in the Earth's foreshock region and the associated wave‐particle interaction are not yet well understood. We investigate the 3‐s ULF waves using Magnetospheric Multiscale (MMS) observations. By combining the plasma rest frame wave properties obtained from multiple methods with the instability analysis based on the velocity distribution in the linear wave stage, the ULF wave is determined to be due to the ion/ion nonresonant mode instability. The interaction between the wave and ions is analyzed using the phase relationship between the transverse wave fields and ion velocities and using the longitudinal momentum equation. During the stage when ULF waves have sinusoidal waveforms up to |dB|/|B0| ~ 3, wheredBis the wave magnetic field andB0is the background magnetic field, the wave electric fields perpendicular toB0do negative work to solar wind ions; alongB0, a longitudinal electric field develops, but theV × Bforce is stronger and leads to solar wind ion deceleration. During the same wave stage, the backstreaming beam ions gain energy from the transverse wave fields and get deceleration alongB0by the longitudinal electric field. The ULF wave leads to electron heating, preferentially in the direction perpendicular to the local magnetic field. Secondary waves are generated within the ULF waveforms, including whistler waves near half of the electron cyclotron frequency, high‐frequency electrostatic waves, and magnetosonic whistler waves. The work improves the understanding of the nature of 3‐s ULF waves and the associated wave‐particle interaction.
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Topological schemes in spacetime for the electrodynamic Aharonov-Bohm effect
Abstract We consider different schemes for the electrodynamic Aharonov-Bohm (AB) effect introduced in Saldanha P. L.,Phys. Rev. A,108(2023) 062218, exploring the phenomenon to enhance the understanding of its topological nature in spacetime. In the treated examples, the electric current in a solenoid varies in time, changing its internal magnetic field and producing an external electric field, while a quantum charged particle is in a superposition state inside two Faraday cages in an interferometer. The Faraday cages cancel the electric field at their interiors, such that the particle is always subjected to null electromagnetic fields. We discuss how the AB phase difference depends on the topology of the electric and magnetic fields in spacetime in the different treated situations. In particular, we discuss interesting results when a conducting wire connects the two Faraday cages, with the AB phase depending on the wire position. We also show an amplification of the AB phase when the wire makes several turns around the solenoid, which could enable an experimental verification of the effect.
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- Award ID(s):
- 2207697
- PAR ID:
- 10598309
- Publisher / Repository:
- IOP Publishing
- Date Published:
- Journal Name:
- Europhysics Letters
- Volume:
- 150
- Issue:
- 4
- ISSN:
- 0295-5075
- Format(s):
- Medium: X Size: Article No. 40003
- Size(s):
- Article No. 40003
- Sponsoring Org:
- National Science Foundation
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