Chalmersnext Labs Maps LNA Power Use Against Qubit Fidelity

A fidelity exceeding eighty per cent across multiple devices was achieved using only approximately SI{0.3}{mW} of power, previously typical operating levels required roughly ten times more. An indium content of sixty per cent within high-electron-mobility transistors provides peak performance for assigning qubits correctly, despite similar noise temperatures to seventy per cent counterparts measured by standard methods. A new method evaluates amplifiers key for reading information from qubits, directly assessing how well these devices perform within a quantum system than in isolation.

The approach revealed that an indium content of sixty per cent in high-electron-mobility transistors delivers peak performance exhibiting noise levels comparable to alternatives with seventy per cent indium. Methods are being refined to accurately assess amplifiers vital for reading information from superconducting qubits; these devices function much like a sensitive microphone preamplifier boosting faint signals without excessive interference. The team developed a new benchmarking technique evaluating amplifier performance *within* an actual quantum system, rather than testing them in isolation as has been standard practice until now.