Suspending superconducting qubits by silicon micromachining

Abstract

We present a method for relieving aluminum 3D transmon qubits from a silicon substrate using micromachining. Our technique is a high yield, one-step deep reactive ion etch that requires no additional fabrication processes, and results in the suspension of the junction area and edges of the aluminum film. The drastic change in the device geometry affects both the dielectric and flux noise environment experienced by the qubit. In particular, the participation ratios of various dielectric interfaces are significantly modified, and suspended qubits exhibited longer $T_1$'s than non-suspended ones. We also find that suspension increases the flux noise experienced by tunable SQUID-based qubits.

Main text: 4 pages, 3 figures. Supplementary materials: 6 pages, 5 figures

References in corpus (10)

• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• Decoherence of flux qubits due to 1/f flux noise
• Experimental evidence for a surface distribution of two-level systems in superconducting lithographed microwave resonators
• Surface participation and dielectric loss in superconducting qubits
• Microwave Dielectric Loss at Single Photon Energies and milliKelvin Temperatures
• Reducing intrinsic loss in superconducting resonators by surface treatment and deep etching of silicon substrates
• Model for l/f Flux Noise in SQUIDs and Qubits
• 1/f Flux Noise in Josephson Phase Qubits
• Observation of directly interacting coherent two-level systems in a solid
• Reduced frequency noise in superconducting resonators

Cited by in corpus (23)

• Towards understanding two-level-systems in amorphous solids -- Insights from quantum circuits
• Analysis and mitigation of interface losses in trenched superconducting coplanar waveguide resonators
• Determining interface dielectric losses in superconducting coplanar waveguide resonators
• Tutorial: Gate-based superconducting quantum computing
• The superconducting quasicharge qubit
• Substrate surface engineering for high-quality silicon/aluminum superconducting resonators
• Resolving the positions of defects in superconducting quantum bits
• Overlap junctions for high coherence superconducting qubits
• Precision measurement of the microwave dielectric loss of sapphire in the quantum regime with parts-per-billion sensitivity
• Effects of Laser-Annealing on Fixed-Frequency Superconducting Qubits
• Superconducting qubits on silicon substrates for quantum device integration
• Mitigation of quasiparticle loss in superconducting qubits by phonon scattering
• Characterization of low loss microstrip resonators as a building block for circuit QED in a 3D waveguide
• Effects of surface treatments on flux tunable transmon qubits
• Protecting superconducting qubits from phonon mediated decay
• Fluxon-Based Quantum Simulation in Circuit QED
• Mitigating Losses of Superconducting Qubits Strongly Coupled to Defect Modes
• Development of transmon qubits solely from optical lithography on 300mm wafers
• Characterization of process-related interfacial dielectric loss in aluminum-on-silicon by resonator microwave measurements, materials analysis, and imaging
• Compact vacuum gap transmon qubits: Selective and sensitive probes for superconductor surface losses
• Dimensional control of tunneling two level systems in nanoelectromechanical resonators
• Enhanced Superconducting Qubit Performance Through Ammonium Fluoride Etch
• Material matters in superconducting qubits