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Induced Quantized Spin Current in Vacuum.

Chong-Sun Chu1, Chun-Hei Leung1

  • 1Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan and Center for Theory and Computation, National Tsing-Hua University, Hsinchu 30013, Taiwan.

Physical Review Letters
|September 24, 2021
PubMed
Summary
This summary is machine-generated.

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The quantum electrodynamics (QED) vacuum, specifically its electrons, becomes spin-polarized in an external electromagnetic field, creating a vacuum spin current. This effect can be measured using a proposed experiment involving liquid crystals.

Area of Science:

  • Quantum electrodynamics (QED)
  • Condensed matter physics
  • Vacuum physics

Background:

  • The quantum vacuum is not empty but filled with virtual particles.
  • External electromagnetic fields can influence quantum vacuum properties.
  • Spin polarization is a key property of particles.

Purpose of the Study:

  • To investigate the effect of external electromagnetic fields on the QED vacuum.
  • To demonstrate the spin polarization of the vacuum electrons.
  • To propose an experimental method for detecting vacuum spin currents.

Main Methods:

  • Theoretical analysis of QED vacuum in external electromagnetic fields.
  • Derivation of vacuum spin polarization and spin current.
  • Proposal of an experimental setup using nematic liquid crystals.

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Main Results:

  • The QED vacuum electrons are shown to be spin-polarized by an external EM field.
  • This spin polarization manifests as a measurable vacuum spin current.
  • The proposed experiment can detect the spin torque from this current.

Conclusions:

  • External electromagnetic fields induce a fundamental effect in the QED vacuum.
  • The vacuum spin current is a detectable phenomenon with potential applications.
  • Nematic liquid crystals offer a viable medium for measuring vacuum spin effects.