Physicists have made the most accurate atomic clock ever made. Physicists at the University of Wisconsin-Madison have produced an optical lattice atomic clock with an accuracy equivalent to 1 second lost every 300 billion years.
Atomic clocks are so precise because they take advantage of the fundamental properties of atoms: when an electron changes its energy level, it absorbs or emits light at the same frequency as all atoms of a particular element. Optical atomic clocks maintain the precision of time by using lasers that precisely match that frequency.
The new atomic clock has gone beyond the standard atomic clock by using multiplexing, in which strontium atoms are split into multiple clocks and arranged in a line in the same vacuum chamber. Using only one atomic clock, the researchers found that their laser could reliably excite electrons in the same number of atoms in only a tenth of a second. However, when they irradiated the laser on two clocks at the same time and compared them, the number of atoms with excitation electrons between the two clocks remained constant for up to 26 seconds. The researchers then conducted thousands of experiments to measure the frequency difference between the two clocks, resulting in a world-accurate chronograph record of just 1 second apart every 300 billion years.
This optical lattice atomic clock is capable of testing ways to find gravitational waves, attempting to detect dark matter, and hopefully discovering new physical phenomena.
Figure 1: This optical lattice atomic clock first requires the strontium atoms to be cooled to near absolute zero in a vacuum chamber.
Figure 2: From a supercooled strontium sphere, scientists multiplex them into six independent spheres, each of which can be used as an atomic clock
Figure 3: Lattice and clock path
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