Chronological feed of everything captured from Lieven Vandersypen.
This research introduces a conditional diffusion model designed to reconstruct high-resolution charge stability diagrams (CSDs) for quantum dot devices from sparse data. By training on approximately 9,000 examples, the model can recover critical charge transition lines from as little as 4% of measured data, significantly outperforming standard interpolation methods in large unmeasured regions.
This work demonstrates significant advancements in preserving spin coherence during qubit transport in silicon quantum dot devices. By combining passive magnetic field gradient reduction, motional narrowing, and dynamical decoupling techniques, the researchers achieved coherence times up to 32 µs. Furthermore, dressed-state shuttling provided robust protection against low-frequency noise without complex pulse control, establishing the viability of mobile spin qubits for scalable silicon quantum processors.
This research demonstrates a silicon spin-qubit architecture leveraging coherent shuttling to enable dynamic connectivity across a sparse array. By utilizing a shuttling bus with four interaction zones, the team implemented weight-four parity checks essential for surface-code error correction and generated a record-breaking five-qubit GHZ state for gate-defined semiconductor spins. This approach reduces the reliance on dense charge-sensing infrastructure, facilitating a modular path toward scalable quantum error correction.
Researchers have successfully performed spectroscopy on an array of eight interacting spins in gate-defined germanium quantum dots. This work advances quantum simulation by demonstrating a method to reconstruct the complete energy spectrum of many-body eigenstates. A significant finding is the observation of a crossover from localization to a chaotic phase as interaction strength increases, indicating progress towards observing complex many-body phenomena.
This paper demonstrates a significant advance in modular quantum computing by achieving entanglement between hole spin qubits in distant germanium registers. The key innovation is a shared-control shuttling link that coherently transfers qubits over micrometers in nanoseconds, mitigating spin-orbit coupling effects. This enables the formation and characterization of Bell states between spatially separated qubits, a crucial step for scaling quantum processors.