Enhanced Superconductivity: Silicides, such as titanium silicide (TiSi2) and niobium silicide (NbSi), exhibit superior superconducting properties compared to the conventional aluminum films used in transmon qubits. These silicides have higher critical temperatures (Tc) and lower residual resistance ratios (RRR), leading to reduced losses and improved coherence times in the qubits.
Improved Josephson Junctions: The formation of silicide layers at the interface between two superconducting layers creates high-quality Josephson junctions. These junctions exhibit more consistent and reliable properties, resulting in better qubit control and reduced decoherence.
Tunable Properties: The introduction of silicides allows for additional tuning parameters in the design of transmon qubits. By varying the thickness and composition of the silicide layer, it is possible to adjust the qubit frequency, anharmonicity, and other relevant parameters. This tunability enables precise optimization of the qubit's performance and mitigates fabrication variations.
Reduced Charge Noise: Silicides can help reduce charge noise in transmon qubits by suppressing two-level fluctuators (TLFs) and other sources of decoherence. The presence of the silicide layer provides a more stable and uniform environment for the qubit, leading to longer coherence times and improved qubit performance.
Increased Fabrication Yield: The use of silicides improves the overall fabrication yield of transmon qubits by reducing the occurrence of defects and shorts. Silicides act as a diffusion barrier, preventing the interdiffusion of different materials and ensuring better isolation between circuit components.
These advantages make silicides a promising material for the fabrication of high-performance transmon qubits, enabling advancements in quantum computing, quantum sensing, and other applications.
