Surface acoustic waves (SAWs) are promising building blocks for quantum interconnects and transducers, but integrating them with semiconductor quantum dots remains challenging. In a new paper, we study flip-chip devices that combine GaAs/AlGaAs or Si/SiGe quantum dots with lithium niobate SAW resonators.

At low temperatures, both platforms ran into trouble due to pyroelectric effects in lithium niobate. GaAs devices suffered unintentional carrier depletion, while Si/SiGe devices experienced frequent electrostatic discharge. These results highlight an important materials challenge for hybrid SAW–qubit systems and suggest that future progress will require non-pyroelectric substrates or alternative coupling schemes.

Dealing with residual exchange in your spin qubits?
Not to worry — we’ve got you covered! Our new preprint explores how to tame residual exchange in singlet–triplet qubits. We introduce two simple strategies: commensurate driving, where you choose pulse lengths that are integer multiples of the Larmor period, and a single-spin coupler scheme that naturally suppresses unwanted interactions. Check it out!

Congratulations to Dr. Feiyang Ye, who defended his thesis entitled “Towards understanding charge noise in Si/SiGe quantum dots!” We will miss you, and we wish you all the best!

Check out our new preprint on using two-level fluctuators in Si quantum dots as temperature probes. Our community has known for a while that voltage pulses heat our qubits, but measuring temperature with a qubit can be challenging. It seems that the defects that create noise for our qubits also experience this heating, potentially offering an easier way to explore this effect.

Welcome to new graduate students Malick Gaye, Fernando Torres Leal, and Zhengyang Zhang. We are excited to have you join the group!

Our paper on using feedback to make noisy fluctuators in silicon quantum dots quieter has been published in Physical Review Applied.

Our paper on the formation of a nuclear-spin dark state in silicon has been published in Nature Physics. We show that using the electrons in quantum dots, we can drive the nuclei into a collective state with a significantly reduced interaction with the electron spins. This state has long been predicted but not observed until now!

Check out our most recent paper: an Editors’ suggestion in Physical Review B about electrical fluctuations in silicon quantum dots.

Our paper on dynamically corrected gates in singlet-triplet qubits has been published as an editors’ suggestion in Physical Review Applied. This work is a collaboration with the group of Ed Barnes at Virginia Tech. Check it out here!

Welcome to one more dilution refrigerator. The fridges are done multiplying…for a while anyway.