Patrik Schach and Enno Giese, physicists at TU Darmstadt, want to redefine time – they believe that our previous measurements may have been inaccurate. The researchers arrived at this suggestion thanks to the phenomenon of quantum tunneling, in which particles appear to move faster than the speed of light.
We understand the world around us using classical mechanics. In this area, the laws of physics prevail, and particles tend to follow them. However, if you dig a little deeper into the quantum realm, even the theory of relativity breaks down.
The faster-than-light movement of particles in a quantum tunnel has led researchers to question whether we have measured time accurately. Schach and Giese have proposed a new experimental design for measuring the time of a tunneling particle, taking into account its unique capabilities in the quantum domain.
What is quantum tunneling?
In classical physics, a particle such as an electron can only pass through a potential energy barrier if it has the energy to overcome it. On the other hand, in quantum mechanics, the particle can overcome such a barrier even if its energy levels are lower. This is called quantum tunneling.
This is attributed to the wave-like properties of the particle in quantum mechanics, which allow it to “tunnel” through the barrier even at a lower energy level. According to quantum mechanics, this tunneling effect is subjectively dependent on the width and height of the barrier as well as the energy of the particle.
Although tunneling also appears to violate the laws of conservation of energy, the particle appears on the other side of the barrier with the same energy as before. So no energy is gained or lost during the process.
Researchers believe that tunneling also plays a role in radioactive decay, allowing particles to leave the nucleus even though they do not have enough energy to escape the nuclear potential barrier. Additionally, the phenomenon could be helpful in applications such as microscopy and memory storage.
According to quantum mechanics, atoms can behave like waves and particles at the same time. Their wave nature can help them overcome an energy barrier. However, when atoms tunnel, it becomes difficult to predict when they will appear on the other side, i.e. when they need to tunnel.
Novel experimental design
Instead of relying on traditional approaches to measuring time, Schach and Giese propose using the tunnel particle as a clock. A non-tunneling particle serves as a reference in such a setup.
By comparing these two natural clocks, the researchers want to determine whether time passes faster, slower or at the same rate as the particle tunnels.
To do this, the researchers want to use the oscillating energy levels between atoms. Using a laser pulse, the researchers cause the atoms to vibrate and start the clock. During tunneling there is a small rhythm shift and a second laser pulse is intended to cause the waves to interfere.
By measuring interference, the team can accurately measure elapsed time. The challenge, however, is that the time difference to be measured is extremely short at 10-26 seconds. To overcome this, the researchers suggest using clouds of atoms instead of individual atoms to amplify the effect.
The experimental design was published in the journal Scientific advances.
ABOUT THE EDITOR
Ameya Paleja Ameya is a science journalist based in Hyderabad, India. A molecular biologist at heart, he traded in the micropipette to write about science during the pandemic and doesn’t want to go back. He enjoys writing about genetics, microbes, technology, and public policy.