Transmon Qubit Using Sn as a Junction Superconductor

Area of Science:

• Quantum computing
• Condensed matter physics
• Materials science

Background:

• Superconducting qubits commonly utilize aluminum-aluminum oxide tunnel junctions for nonlinear inductance.
• Exploring alternative materials for qubit fabrication is crucial for advancing quantum technologies.

Purpose of the Study:

• To realize transmon qubits using InAs semiconductor nanowires coated with β-Sn superconducting shells.
• To investigate the tunability of qubit frequency and coherence times in these novel devices.

Main Methods:

• Fabrication of transmon qubits with InAs nanowire cores and β-Sn superconducting shells.
• Utilizing gate voltage to tune Josephson energy and qubit frequency.
• Measuring energy relaxation time (T1) and echo dephasing time (T2) to assess coherence.

Main Results:

• Successfully realized tunable transmon qubits with a frequency range of 3 GHz.
• Achieved a maximum energy relaxation time (T1) of 27 μs at lower frequencies.
• Obtained a maximum echo dephasing time (T2) of 1.8 μs at higher frequencies.

Conclusions:

• InAs nanowire-based superconducting qubits offer a promising platform for quantum information processing.
• Coherence times are influenced by qubit frequency, with potential for enhancement through improved fabrication and circuit design.