Qubit ZooImproved merged-element transmon using micrometer-scale Al/AlOₓ/Al overlap junctions with optimized long oxidation. Demonstrates T₁ = 10–90 μs with annealed devices exceeding 100 μs. Shows that junction loss is not the primary coherence limiter in small-junction transmons, suggesting a path to high-coherence compact qubits.
Key Results
- T₁: 10–90 μs (up to >100 μs with annealing)
- Micrometer-scale overlap junctions with long oxidation
- Low subgap conduction indicates high-quality tunnel barrier
- Junction loss is NOT the dominant limiter
- Path to high-coherence compact qubits via improved barrier materials
Links
- Journal: Physical Review Applied
- arXiv: 2103.09163