Kavli Affiliate: Gary Steele | Summary:Recent studies find that even drives far below the superconducting gap frequency may cause drive-induced quasiparticle generation (QPG) across Josephson junctions (JJs) of superconducting qubits (SCQs), posing a serious concern for fault-tolerant superconducting quantum computing (FTSQC). Nonetheless, quantitative experimental estimation on QPG rates has remained vague. Here, we investigate QPG […]

Kavli Affiliate: Leonardo Dicarlo | Summary:Leakage to non-computational states is a source of correlated errors in both time and space that limits the effectiveness of quantum error correction (QEC) with superconducting circuits. We present and experimentally demonstrate a high-fidelity, leakage reduction unit (LRU) operating concurrently with transmon measurement without incurring time overhead. Adapted from double-drive […]

Kavli Affiliate: Herre Van Der Zant | Summary:The interaction between itinerant electrons and localized spins is key to a wide range of electronic phenomena. Of particular interest is the regime where the interacting electrons exhibit both spin and valley degeneracy, resulting in SU(4) Kondo physics. However, this regime is challenging to realize in typical mesoscopic […]

Kavli Affiliate: Stephanie Wehner | Summary:The aim of a quantum network is to enable the generation of end-to-end entangled links between end nodes of the network, so that they can execute quantum network applications. To facilitate this, it is desirable to have robust control of the network in order to be able to provide a […]

Kavli Affiliate: Ronald Hanson | Summary:The tin-vacancy center in diamond (SnV) has emerged as a compelling building block for realizing next-generation quantum networks thanks to its excellent optical and spin properties. Coupling to photonic crystal cavities (PCCs) promises to further enhance the SnV light-matter interface and unlock a diverse range of entanglement generation protocols. Recent […]

Kavli Affiliate: Michael Wimmer | Summary:We theoretically explore the electronic structure of holes in cylindrical Germanium/Silicon core/shell nanowires using a perturbation theory approach. The approach yields a set of interpretable and transferable effective low-energy models for the lowest few sub-bands up to fifth order for experimentally relevant growth directions. In particular, we are able to […]

Kavli Affiliate: Mazhar Ali | Summary: Josephson junctions are essential devices in superconducting electronics and quantum computing hardware. Here we predict electrical control of the supercurrent in composite superconductor-insulator-ferroelectric-insulator-superconductor (S-I-FE-I-S) Josephson junctions. Inversion symmetry broken by unequal dielectric barrier thicknesses and/or potentials converts ferroelectric polarization reversal into a substantial change of the critical current. With […]

Kavli Affiliate: Wolfgang Tittel | Summary:We characterize the spectroscopic and coherence properties of the 1451.37 nm excited-state zero-phonon line (ZPL) between the $^3F_4$ and the $^3H_4$ manifolds of a thulium-doped yttrium aluminum perovskite ($textTm^3+$:$textYAlO_3$) crystal at temperatures around 1.5 K. We measure the absorption spectrum between the $^3H_6$ – $^3F_4$ and $^3F_4$ – $^3H_4$ manifolds, […]

Kavli Affiliate: Wolfgang Tittel | Summary:We characterize spectroscopic and coherence properties of the 1451.37 nm excited-state zero-phonon line (ZPL) between the $^3F_4$ and the $^3H_4$ manifolds of a thulium-doped yttrium aluminum perovskite (Tm$^3+$:YAlO$_3$) crystal at temperatures around 1.5 K. We measure the absorption spectrum between the $^3H_6$ – $^3F_4$ and $^3F_4$ – $^3H_4$ manifolds, the […]

Kavli Affiliate: Menno Veldhorst | Summary:Quantum simulators enable studies of many-body phenomena which are intractable with classical hardware. Spins in devices based on semiconductor quantum dots promise precise electrical control and scalability advantages, but accessing many-body phenomena has so far been restricted by challenges in nanofabrication and simultaneous control of multiple interactions. Here, we perform […]