New Spin on Famous Physics Experiment Shows Light Interfering With Its Own Past

Thomas Young, a British scientist, performed the famous "double slit" experiment in 1801, demonstrating that light behaved like a wave by passing through two slits in a material at the same time and interfering in predictable ways when they recombined.

The experiment has been replicated since that ground-breaking occasion to show electromagnetic radiation exhibits both wave-like and particle-like properties. To put it another way, depending on how it is measured, light may behave in two different ways, like marbles rolling down a slope or like ripples in a pond.

Additionally, not just photons behave in this manner. Scientists have demonstrated that electrons, neutrons, and whole atoms behave in the same way using comparable settings, proving a fundamental principle of quantum physics as a theory based on chance.

Modern modifications have been made to Young's experiment by scientists. To investigate whether a wave of light may interfere with its own past and future, they employed "time slits" made by quick changes in the reflectance of a material in place of a pair of slits separated in space.

Riccardo Sapienza, a physicist from Imperial College London in the UK, believes that the experiment "reveals more about the fundamental nature of light and serves as a stepping stone to creating the ultimate materials that can minutely control light in both space and time."

Indium tin oxide, a substance used in smartphone screens, was applied in a thin layer by Sapienza and his associates. A single wave of light can interfere with itself by traveling along several courses in time as a result of the laser pulses' alteration of the material's reflectance.

Due to the altered frequency of the light caused by the temporal variations, unique colors, rather than variations in brightness, were produced when the light hit the material. The interference pattern was examined by the scientists in order to draw conclusions concerning the wave-like nature of the light.

According to physicist John Pendry of Imperial College London, "The double time slits experiment opens the door to a completely new spectroscopy capable of resolving the temporal structure of a light pulse."

Interestingly, the slits opened up between one and ten femtoseconds faster than the researchers anticipated. (quadrillionths of a second). The fact that the experiment exceeded the theoretical modeling shows that some of that modeling needs to be reexamined since materials may not interact with light exactly as scientists had previously believed they would. (when intensity or speed changes, for example).

This kind of material, which can alter its response to light in incredibly brief bursts, may be valuable for creating new technologies and unlocking the secrets of quantum physics.

The study of phenomena like black holes will benefit from it even on the greatest scales. The team's next goal is to apply its "time twist" to the atomic crystal, a material in which atoms are arranged in a precise pattern that might hasten the development of electronics.

According to physicist Stefan Maier of Imperial College London, "the idea of time crystals has the potential to lead to ultrafast, parallelized optical switches."

The research has been published in Nature Physics.