Oscilloscope in Electronic Testing Lab
Uwe Moser/Alamy
Recent findings suggest that microwaves can exist in a state referred to as “imaginary time” within certain materials. This peculiar behavior has previously lacked tangible confirmation in laboratory settings.
When beams of radiation, like microwaves or light, traverse a material, they can disrupt atomic interactions, resulting in time delays. In 2016, researchers calculated that these time delays might be conceptualized as imaginary. This involves multiplying a few seconds by the square root of -1, known as an imaginary number denoted by I. While such numbers typically do not appear in practical scenarios, Isabella Giovanneli and Stephen Anlage at the University of Maryland devised a method to measure them experimentally.
“It represents an overlooked dimension that people have disregarded,” explains Anlage. “We’ve managed to expose it and attribute a physical significance to it.”
For their investigations, the researchers directed microwave pulses through a network of coaxial cables arranged in a ring. They meticulously controlled the incoming pulses and evaluated the microwave feedback with impressive precision. Using an oscilloscope and other instruments, they measured not only the duration the signals persisted in the cables but also how properties like frequency were modified.
They found that so-called imaginary time is evidenced by a slight physical alteration. Microwaves do not remain static in the cables; instead, they oscillate at a slightly altered frequency. This variation occurs due to the dynamic interaction of microwave energy within the cables. Konstantin Bliokh conducted analysis on this in 2016 at the Donostia International Physics Centre in Spain.
Previous studies overlooked imaginary time delays as researchers considered them to be non-physical. Giovanneli highlights the challenges of detecting these subtle frequency shifts: “The difficulty was significant, and our ability to measure this effectively was mainly due to having the world’s top oscilloscope,” she adds.
Franco Nori at Riken in Japan, who also contributed to the 2016 work, described the new experiments as “original, thoughtful, meticulously carried out, and significant.” While he and his team validated a portion of the actual—real part of the process, Anlage and Giovanneli’s research provided a comprehensive insight into how materials modulate radiation pulses.
“Previously, such effects were deemed trivial, but they are increasingly crucial in nanoscience,” notes Brioch. He believes that when applied to more intricate systems, these findings could enhance various sensing devices. Nori suggested that the outcomes could also boost technologies using light for data storage, such as certain types of computer memory.
The team is now investigating how the observed frequency shifts correlate with the transmission of information-carrying pulses, like those used in communications, as they navigate through materials.
“We’ve created the hammer, and now it’s time to discover the nails,” concludes Anlage.
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Source: www.newscientist.com