Quantum computations require qubits to be cooled to millikelvin temperatures to minimize noise. However, managing quantum circuits with electronics generates heat, which is challenging to dissipate at such low temperatures.
Current technologies separate quantum circuits from electronic components, limiting scalability beyond the laboratory due to inefficiencies and noise.
A team at EPFL’s Laboratory of Nanoscale Electronics and Structures (LANES) has developed a device that operates at extremely low temperatures with efficiency comparable to room temperature technologies.
“We are the first to create a device that matches current technologies’ conversion efficiency but operates at low magnetic fields and ultra-low temperatures required for quantum systems. This work is truly a step ahead,” says LANES PhD student Gabriele Pasquale.
The device combines graphene’s conductivity with indium selenide’s semiconductor properties, delivering unparalleled performance due to its unique two-dimensional structure.
The device utilizes the Nernst effect, a thermoelectric phenomenon that produces an electrical voltage when a magnetic field is applied to an object experiencing varying temperatures. The two-dimensional quality of the lab’s device allows for efficient manipulation of this mechanism through electrical means.
The 2D structure developed at EPFL has made a breakthrough in quantum technology by utilizing a laser as a heat source and a specialized dilution refrigerator reaching 100 millikelvin. This novel device overcomes the challenge of converting heat to voltage at low temperatures through harnessing the Nernst effect, filling a crucial gap in quantum technology.
“Our device could provide the necessary cooling to prevent heat from disturbing qubits in quantum computing systems,” says Pasquale.
Pasquale emphasizes the research’s importance in uncovering thermopower conversion at low temperatures. The LANES team is confident their device can be seamlessly integrated into existing low-temperature quantum circuits.
“These findings hold promise for developing advanced cooling technologies essential for quantum computing at millikelvin temperatures,” Pasquale says. “We believe this achievement could revolutionize cooling systems for future technologies.”
Journal reference:
- Pasquale, G., Sun, Z., Migliato Marega, G. et al. Electrically tunable giant Nernst effect in two-dimensional van der Waals heterostructures. Nature Nanotechnology, 2024; DOI: 10.1038/s41565-024-01717-y
