MIT News February 21, 2023
To overcome errors in the qubits due to heat in quantum systems, researchers at MIT developed a wireless communication system that enables a quantum computer to send and receive data to and from electronics outside the refrigerator using high-speed terahertz waves. A transceiver chip, cryostat, placed inside the fridge sends and receives data from a terahertz wave source outside the cryostat using backscatter. An array of antennas on top of the chip, each of which is only about 200 micrometers in size, act as tiny mirrors. These mirrors can be “turned on” to reflect waves or “turned off.” The process generates only a minimal amount of heat. Because terahertz waves have lower frequencies than the light waves used in photonic systems, the terahertz waves carry less quantum noise, which leads to less interference with quantum processors. The transceiver chip and terahertz link can be fully constructed with standard fabrication processes on a CMOS chip, so they can be integrated into many current systems and techniques. The researchers were able to transmit data at 4 gigabits per second. The downlink of the contactless system posed about 10 times less heat load than a system with metallic cables, and the temperature of the cryostat fluctuated up to a few millidegrees during experiments. According to the researchers they plan to improve the system’s speed and efficiency using special terahertz fibers and improve scalability. Incorporating this technology into the system could make the device more cost-effective. Their paper will be presented at the upcoming International Solid-States Circuits Conference… read more.
…transceiver chip the researchers developed that is placed inside a complex refrigerator that houses a quantum computer. Credits: Image by Jinchen Wang