Scientists have just discovered a whole new way to measure time: ScienceAlert
Marking the passage of time in a world of ticking clocks and swinging pendulums is a simple case of counting the seconds between ‘then’ and ‘now’.
At the bottom of the quantum scale, however, ‘then’ cannot always be foreseen of buzzing electrons. Worse, “now” often fades into a haze of uncertainty. A stopwatch just won’t cut it in some scenarios.
A possible solution could be found in the form of the quantum fog itself, say researchers at Uppsala University in Sweden.
Their experiments with the wave-like nature of something called a Rydberg state have revealed a new way of measuring time that doesn’t require a precise starting point.
Rydberg atoms are the over-inflated balloons of the particle realm. Blown up with lasers instead of air, these atoms contain electrons in extremely high energy states, orbiting far from the nucleus.
Of course, not every pump of a laser has to blow up an atom to cartoonish proportions. In fact, lasers are routinely used to tickle electrons in higher energy states for various purposes.
In some applications, a second laser can be used to track changes in the electron’s position, including the passage of time. This one ‘pump probeFor example, ‘techniques can be used to measure the speed of certain ultra-fast electronics.
Inducing atoms in Rydberg states is a handy trick for engineersnot least when it comes to designing new components in front of quantum computers. Needless to say, physicists have accumulated a significant amount of information about the way electrons move when pushed into a Rydberg state.
However, being quantum animals, their moves are less like beads sliding across a small abacus, and more like an evening at the roulette table, where every roll and jump of the ball is squeezed into a single game of chance.
The mathematical rulebook behind this wild game of Rydberg electron roulette is called a Rydberg wave pack.
Like real waves in a pond, having more than one Rydberg wave packet lapping in a space causes interference, resulting in unique ripple patterns. Throw enough Rydberg wave packs into the same atomic pond, and those unique patterns will each represent the different time it takes for the wave packs to evolve in harmony with each other.
It was these “fingerprints” of time that the physicists behind this latest set of experiments wanted to test, demonstrating that they were consistent and reliable enough to serve as a form of quantum time stamping.
Their research involved measuring the results of laser-excited helium atoms and matching their findings with theoretical predictions to show how their signature results might hold up over time.
“When you use a counter, you have to define zero. You start counting at some point,” explained physicist Marta Berholts of Uppsala University in Sweden, who led the team. new scientist.
“The advantage of this is that you don’t have to start the clock — you just look at the interference structure and say ‘okay, it’s been 4 nanoseconds’.”
A guide to evolving Rydberg wave packages could be used in conjunction with other forms of pump-probe spectroscopy that measure events on a small scale, when they are occasionally less obvious, or just too clumsy to measure.
Importantly, none of the fingerprints need a then and now to serve as the starting and stopping point for time. It would be like measuring the race of an unknown sprinter against some competitors running at certain speeds.
By searching for the signature of disturbing Rydberg states amid a sample of pump probe atoms, engineers were able to detect a timestamp for events as fleeting as just 1.7 trillionths of a second.
Future experiments with quantum watches could replace the helium with other atoms, or even use laser pulses of different energies, to extend the timestamps guide to a wider range of conditions.
This research was published in Physical Assessment Exam.
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