Mechanical force in laser cooling and trapping

Yukiko Shimizu, Hiroyuki Sasada

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Laser cooling and trapping are based on the mechanical force an electromagnetic wave (EMW) exerts upon an atom. The force is generally explained as the result of the conservation law of the linear momentum of a photon and the atom. In contrast, we have directly derived the force from primary electromagnetism in order to clarify its origin. We regarded the atom as an electric dipole moment induced by the EMW, and examined the interaction between the dipole moment and the EMW. We applied a semiclassical theory in which the atom is quantized as a two-level system but the electromagnetic field is not; no photon is introduced. The results are consistent with the commonly accepted explanation, and explicitly demonstrate the contribution of the electric and magnetic fields to the force, in particular, the significance of the longitudinal magnetic field for the dipole force in laser trapping.

Original languageEnglish
Pages (from-to)960-967
Number of pages8
JournalAmerican Journal of Physics
Volume66
Issue number11
Publication statusPublished - 1998 Nov

Fingerprint

laser cooling
trapping
electromagnetic radiation
atoms
dipole moments
photons
electric moments
conservation laws
magnetic fields
electric dipoles
electromagnetic fields
electromagnetism
dipoles
momentum
electric fields
lasers
interactions

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Shimizu, Y., & Sasada, H. (1998). Mechanical force in laser cooling and trapping. American Journal of Physics, 66(11), 960-967.

Mechanical force in laser cooling and trapping. / Shimizu, Yukiko; Sasada, Hiroyuki.

In: American Journal of Physics, Vol. 66, No. 11, 11.1998, p. 960-967.

Research output: Contribution to journalArticle

Shimizu, Y & Sasada, H 1998, 'Mechanical force in laser cooling and trapping', American Journal of Physics, vol. 66, no. 11, pp. 960-967.
Shimizu Y, Sasada H. Mechanical force in laser cooling and trapping. American Journal of Physics. 1998 Nov;66(11):960-967.
Shimizu, Yukiko ; Sasada, Hiroyuki. / Mechanical force in laser cooling and trapping. In: American Journal of Physics. 1998 ; Vol. 66, No. 11. pp. 960-967.
@article{cc1136b108464f73a657d9214ca4f411,
title = "Mechanical force in laser cooling and trapping",
abstract = "Laser cooling and trapping are based on the mechanical force an electromagnetic wave (EMW) exerts upon an atom. The force is generally explained as the result of the conservation law of the linear momentum of a photon and the atom. In contrast, we have directly derived the force from primary electromagnetism in order to clarify its origin. We regarded the atom as an electric dipole moment induced by the EMW, and examined the interaction between the dipole moment and the EMW. We applied a semiclassical theory in which the atom is quantized as a two-level system but the electromagnetic field is not; no photon is introduced. The results are consistent with the commonly accepted explanation, and explicitly demonstrate the contribution of the electric and magnetic fields to the force, in particular, the significance of the longitudinal magnetic field for the dipole force in laser trapping.",
author = "Yukiko Shimizu and Hiroyuki Sasada",
year = "1998",
month = "11",
language = "English",
volume = "66",
pages = "960--967",
journal = "American Journal of Physics",
issn = "0002-9505",
publisher = "American Association of Physics Teachers",
number = "11",

}

TY - JOUR

T1 - Mechanical force in laser cooling and trapping

AU - Shimizu, Yukiko

AU - Sasada, Hiroyuki

PY - 1998/11

Y1 - 1998/11

N2 - Laser cooling and trapping are based on the mechanical force an electromagnetic wave (EMW) exerts upon an atom. The force is generally explained as the result of the conservation law of the linear momentum of a photon and the atom. In contrast, we have directly derived the force from primary electromagnetism in order to clarify its origin. We regarded the atom as an electric dipole moment induced by the EMW, and examined the interaction between the dipole moment and the EMW. We applied a semiclassical theory in which the atom is quantized as a two-level system but the electromagnetic field is not; no photon is introduced. The results are consistent with the commonly accepted explanation, and explicitly demonstrate the contribution of the electric and magnetic fields to the force, in particular, the significance of the longitudinal magnetic field for the dipole force in laser trapping.

AB - Laser cooling and trapping are based on the mechanical force an electromagnetic wave (EMW) exerts upon an atom. The force is generally explained as the result of the conservation law of the linear momentum of a photon and the atom. In contrast, we have directly derived the force from primary electromagnetism in order to clarify its origin. We regarded the atom as an electric dipole moment induced by the EMW, and examined the interaction between the dipole moment and the EMW. We applied a semiclassical theory in which the atom is quantized as a two-level system but the electromagnetic field is not; no photon is introduced. The results are consistent with the commonly accepted explanation, and explicitly demonstrate the contribution of the electric and magnetic fields to the force, in particular, the significance of the longitudinal magnetic field for the dipole force in laser trapping.

UR - http://www.scopus.com/inward/record.url?scp=0032358127&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032358127&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0032358127

VL - 66

SP - 960

EP - 967

JO - American Journal of Physics

JF - American Journal of Physics

SN - 0002-9505

IS - 11

ER -