Turning Heat into Electricity to Keep Quantum Computers Cool

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One of the main reasons we haven’t built a fully operational, powerful quantum computer that could perform large-scale calculations is that we don’t have the technology to keep quantum computers cool – the qubits in quantum computers require temperatures of about -270°C to function.

To this end, researchers at the Swiss Federal Institute of Technology Lausanne (EPFL) developed a 2D micrometer-sized thermoelectric device that can efficiently convert heat into electricity at temperatures that are suitable for qubits to operate.

Lead researcher Gabriele Pasquale explains: “If you think of a laptop in a cold office, the laptop will still heat up as it operates, causing the temperature of the room to increase as well. In quantum computing systems, there is currently no mechanism to prevent this heat from disturbing the qubits. Our device could provide this necessary cooling.”

According to Interesting Engineering, this 2D device harnesses the Nernst effect, which enables the device to efficiently generate electrical voltage in a quantum system in response to temperature changes when a perpendicular magnetic field is applied. Moreover, the device is made using graphene and indium selenide (known for high electrical conductivity and excellent semiconductor properties, respectively), which combined with the Nernst effect enable the device to cool down a quantum system and effectively manage the heat produced by the components of its quantum circuit.

The researchers tested whether the 2D device could make a system efficiently work at extremely cool temperatures when the system is exposed to a heating source – they used it in an environment cooled to the temperature needed for the qubits to work, then used a laser to heat the system. The 2D device successfully managed to turn heat into electricity.

This experiment proves that it is indeed possible to achieve the cooling technologies that would make a quantum system work, bringing us closer to feasible and scalable quantum computing applications.