Isotopically Enhanced Triple-Dot Qubits in SiGe
Abstract: Qubits based on silicon offer the promise of low magnetic noise due to isotopic enhancement and the availability of existing silicon growth and fabrication processes. Triple-dot qubits offer promise of exchange-only spin-qubit control, enabling operation using only gate voltages. The main impediments to silicon qubits are interface disorder, charge noise, valley degeneracy, and nuclear magnetism. In this talk, I will summarize recent data characterizing these impediments for SiGe triple dots fabricated in an undoped accumulation-mode gate architecture, including symmetric barrier control to mitigate charge noise, and isotopic enhancement to mitigate nuclear noise. I will then discuss the mathematics of pulse sequences allowing gauge-independent quantum logic, enabling future developments for exchange-only multiqubit quantum processors.
Updated location for this week's talk: Talk will begin at 12 noon in 201 E. Bridge. Lunch will be available following the talk in 114 E. Bridge.