A Refrigerator so Cold It Turns Atoms into Their Quantum States

A team of researchers have used superconductivity to create a fridge that could cool atoms to nearly absolutely zero temperatures.

Professor of Physics at the University of Rochester, Andrew Jordan and his team have conceived a refrigerator that could cool atoms to below 459 degrees Fahrenheit. That's cold, very cold.

If not for food storage, what could a refrigerator possibly be used for?

This specific fridge, based on the property of superconductivity, would facilitate and enhance the performance of quantum sensors or circuits for ultrafast quantum computers.

RELATED: SCIENTISTS MAKE ARTIFICIAL ATOMS THAT CAN POWER QUANTUM TECHNOLOGY

Let’s break it down first.

What is superconductivity, and what is it useful for?

Conductivity is how well a material conducts electricity. High conductivity materials are those that allow electric current to flow through it; for example, metals. Even good conductors, like metals, still encounter resistance due to friction though.

A superconductor, on the other hand, is when a material conducts electricity without encountering any resistance, thus without losing any energy.

Researchers believe all metals become superconductors if their temperatures can be lowered enough. The tricky part is knowing the exact ‘critical temperature’ for each metal, as these all differ.

"When you reach this magical temperature -and it's not a gradual thing, it's an abrupt thing - suddenly the resistance just drops like a rock to zero and there is a phase transition that happens," Jordan says. "A practical superconducting fridge, as far as I know, has not been done at all."

What is the difference between a superconducting quantum fridge and the ones in our kitchens?

The superconducting quantum refrigerator uses the principles of superconductivity to create an ultra-cold environment. This cold environment is then used to generate the desired and required quantum effects to enhance quantum technologies.

Different to our kitchen fridges, this superconducting quantum fridge would create an environment where researchers could change materials into a superconductive state – for example changing a material to a gas or liquid.

While superconducting quantum refrigerators would not be for use in a person's kitchen, the operating principles are quite similar to traditional refrigerators, Jordan says.

"What your kitchen fridge has in common with our superconducting refrigerators is that it uses a phase transition to get a cooling power."

Similar to a superconducting quantum refrigerator, a conventional refrigerator operates by removing heat, not by making the contents cold. It moves a fluid – the refrigerant – between hot and cold reservoirs, changing it from a liquid to a gas.

The main difference between the two refrigerators is that, a superconductor fridge’s refrigerant doesn’t change from a liquid state to a gas, its electrons change from the paired superconducting state to an unpaired normal state.

If not storing milk and vegetables, what will researchers place inside the superconductor fridge?

Instead of food storage, the superconducting quantum refrigerator could be used to store qubits, the basic units of quantum computers. They could also be used to cool quantum sensors which measure light extremely efficiently and are used for studying stars and other galaxies, and they could also be used to develop better imaging in MRI machines.

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"It's really kind of amazing to think about how this works. It's all basically taking energy and converting it into a transformative heat," says Jordan.

Not what regular Jack and Jill store in their fridge, but potentially very useful for the advancement of science.

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