Optical lattice clock and magnetic field correction method for optical lattice clock

Patent metadata

Field	Value
Publication number	US-11894854-B2
Application number	US-202117915776-A
Country	US
Kind code	B2
Filing date	Mar 30, 2021
Priority date	Mar 31, 2020
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

An optical lattice clock includes a clock transition space having disposed therein an atom group trapped in an optical lattice, and a triaxial magnetic field correction coil for correcting the magnetic field of the clock transition space. Additionally, in a correction space that includes the clock transition space and is larger than the clock transition space, a photoreceiver promotes the clock transition of the atom group trapped in the optical lattice and acquires a clock transition frequency distribution for the correction space. Further, a corrector corrects the magnetic field of the triaxial magnetic field correction coil on the basis of the frequency distribution measured by the photo receiver.

First claim

The invention claimed is:

1. An optical lattice clock, comprising:
a clock transition space in which an atom population confined in an optical lattice is arranged;
a triaxial magnetic field correction coil that corrects a magnetic field in the clock transition space;
obtainment means for prompting clock transition of the atom population confined in the optical lattice in a correction space that includes the clock transition space and is larger than the clock transition space, and obtaining a frequency distribution of the clock transition in the correction space; and
correction means for correcting the magnetic field of the triaxial magnetic field correction coil, based on the frequency distribution obtained by the obtainment means.

2. The optical lattice clock according to claim 1 , further comprising
movement means for moving the atom population confined in the optical lattice, by a moving optical lattice,
wherein the obtainment means obtains the frequency distribution of the clock transition in the correction space, by measuring a frequency of the clock transition of the atom population at a plurality of locations in the correction space moved by the movement means.

3. The optical lattice clock according to claim 1 ,
wherein the triaxial magnetic field correction coil comprises: a first coil group configured to correct only a constant term and a first order spatial derivative term in the magnetic field, and a second coil group configured to correct second and higher order spatial derivative terms in the magnetic field, and
the correction means adjusts a current caused to flow to the second coil group and corrects the higher order spatial derivative terms, based on the frequency distribution, and subsequently adjusts a current caused to flow to the first coil group and corrects the constant term and the first order spatial derivative term.

4. The optical lattice clock according to claim 1 ,
wherein the obtainment means obtains the frequency distribution of the clock transition in the correction space, by spatially detecting light of the clock transition emitted by the atom population distributed entirely over the correction space.

5. The optical lattice clock according to claim 1 ,
wherein the correction space extends on both sides of the clock transition space, along each axis on which photons of the optical lattice are arranged.

6. A method of correcting a magnetic field of an optical lattice clock, the optical lattice clock comprising:
a clock transition space in which an atom population confined in an optical lattice is arranged; and
a triaxial magnetic field correction coil that corrects a magnetic field in the clock transition space,
the method comprises:
prompting clock transition of the atom population confined in the optical lattice in a correction space that includes the clock transition space and is larger than the clock transition space, and obtaining a frequency distribution of the clock transition in the correction space; and
correcting the magnetic field of the triaxial magnetic field correction coil, based on the obtained frequency distribution.

Assignees

• Jeol Ltd
• Riken

Inventors

• Tsuji Shigenori
• Takamoto Masao
• Katori Hidetoshi

Classifications

• G21K1/30

  for confining neutral particles or handling confined neutral particles, e.g. atom traps · CPC title

• H03L7/26 Primary

  using energy levels of molecules, atoms, or subatomic particles as a frequency reference · CPC title

• G04F5/145

  using Coherent Population Trapping · CPC title

• G04F5/14 Primary

  using atomic clocks · CPC title

• H01S1/06

  Gaseous {, i.e. beam masers} · CPC title