Keeping the energy in the room

It may seem like technology keeps getting better. A team of scientists and engineers are hard at work to improve the world.

Ben Mazin is a professor at UC Santa Barbara. In a paper published in Physical Review Letters, he and his team improved the resolution of their sensor, a major step towards analyzing the composition of exoplanets.

Nicholas Zobrist said that they were able to double the power of their detectors.

This is the largest energy resolution increase we have ever seen. It opens up a whole new path to science goals.

An MKID is a type of sensor. Semiconductors like Silicon are used in most light detectors. The photo-electric effect causes a photon to hit the sensor and knock off an electron that can be used to detect a signal.

Electricity can flow without resistance with the use of a superconductor. These materials have other useful qualities. Semiconductors have a gap energy that needs to be knocked out. Even faint signals can be detected by the related gap energy in a superconductor.

A single photon can cause a lot of electrons to be knocked off of a superconductor. The energy of the light can be determined by measuring the number of electrons. The energy of the photon tells us a lot about what happened.

It's leaking energy.

The researchers had reached a point where they couldn't make them very sensitive. The device was found to be leaking energy from the superconductor into the wafer. The signal looked weaker than it really was.

Mobile electrons carry the current in electronics. They have a tendency to interact with their surroundings and lose energy in the process. There are two electrons in a superconductor, one spin up and one spin down, and they are able to move about without resistance.

It is similar to a couple at a club. Two people can move through the crowd with no resistance. A single person stops to talk to everyone else.

The electrons are grouped up. They're all dancing together without interacting with other couples because they're all gazing into each other's eyes.

He said that a photon hitting the sensor was like someone spilling a drink on a partner. One partner stumbled into other couples and created a commotion. The cascade of mobile electrons is measured by theMKID.

At the edge of the dance floor, this can happen. The offended party stumbled out of the club. It was great for the dancers but not for the scientists. The light signal will not be as strong if this happens.

They are fencing in.

The authors discovered that a thin layer of metal indium was placed between the sensor and the substrate. The dancers were kept in the room and interacted with the rest of the crowd by the indium.

They chose indium because it is a superconductor at the temperatures at which they will operate. The team was challenged by the metal. It has a tendency to clump up. It's not good for making a thin, uniform layer.

Their hard work paid off. The wavelength measurement uncertainty was cut in half. The system can now measure a photon with a wavelength of 1000 nanometers. "This has real implications for the science we can do, because we can better resolve the spectrum of the objects that we're looking at."

Different phenomena emit and absorb certain types of light. Scientists are able to identify the composition of objects both nearby and across the entire visible universe using this light.

The detectors are being applied to exoplanet science. Scientists can only study a small group of exoplanets right now. The planet needs to pass between the stars in order for researchers to see it. The signal to noise ratio is not good for rocky planets.

The light reflected off the surface of a planet can be used by scientists. The next generation of telescopes will be able to see this.

The group is experimenting with a completely different approach to the problem. The paper's results are impressive, but Mazin thinks the indium technique could be obsolete if his team succeeds. He said that the scientists are close to their goals.

More information: Nicholas Zobrist et al, Membraneless Phonon Trapping and Resolution Enhancement in Optical Microwave Kinetic Inductance Detectors, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.129.017701 . On Arxiv: arxiv.org/abs/2204.13669 Journal information: Physical Review Letters , arXiv