Person:
Joe, Graham

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Joe

First Name

Graham

Name

Joe, Graham

Filters

2024 - 20252

Settings

Author's Publications: search.filters.isAuthorOfPublication.b8e47046-db38-4fba-92a3-3e1f2cc36304

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Publication
    Coherent Control of a Superconducting Qubit Using Light
    (2025-01-03) Warner, Hana; Xin, C. J.; Sete, Eyob; Langley, Brandon; Reagor, Matthew; Loncar, Marko; Holzgrafe, Jeffrey; Yankelevich, Beatriz; Barton, David; Sinclair, Neil; Zhu, Di; Batson, Emma; Colangelo, Marco; Shams Ansari, Amirhassan; Joe, Graham; Berggren, Karl; Jiang, Liang; Poletto, Stefano
    Quantum communications technologies require a network of quantum processors connected with low loss and low noise communication channels capable of distributing entangled states. Superconducting microwave qubits operating in cryogenic environments have emerged as promising candidates for quantum processor nodes. However, scaling these systems is challenging because they require bulky microwave components with high thermal loads that can quickly overwhelm the cooling power of a dilution refrigerator. Telecommunication frequency optical signals, meanwhile, can be fabricated in significantly smaller form factors while avoiding challenges due to high signal loss, noise sensitivity, and thermal loads due to their high carrier frequency and propagation in silica optical fibers. Transduction of information via coherent links between optical and microwave frequencies is therefore critical to leverage the advantages of optics for superconducting microwave qubits, while also enabling superconducting processors to be linked with low-loss optical interconnects. Here, we demonstrate coherent optical control of a superconducting qubit. We achieve this by developing a microwave-optical quantum transducer that operates with up to 1.18% conversion efficiency with low added microwave noise, and demonstrate optically-driven Rabi oscillations in a superconducting qubit.
  • No Thumbnail Available
    Publication
    Controlling interactions between high frequency phonons and single quantum systems using phononic crystals
    (SpringerNature, 2024-12-18) Sinclair, Neil; Haas, Michael; Joe, Graham; Ding, Sophie Weiyi; Jin, Chang; Xin, C.J.; Yeh, Matthew; Loncar, Marko
    The ability to control phonons in solids is key in many fields of quantum science, ranging from quantum information processing to sensing. Phonons often act as a source of noise and decoherence when solid-state quantum systems interact with the phonon bath of their host matrix. In this study, we demonstrate the ability to control the phononic local density of states of the host matrix using phononic crystals and measure its positive impact on single quantum systems. We design and fabricate diamond phononic crystals with features down to around 20 nm, resulting in a high-frequency complete phononic bandgap from 50 to 70 GHz. The engineered local density of states is probed using single silicon-vacancy colour centres embedded in the phononic crystals. We observe an 18-fold reduction in the phonon-induced orbital relaxation rate of the emitters compared to bulk, thereby demonstrating that the phononic crystal suppresses spontaneous single-phonon processes. Furthermore, we show that our approach can efficiently suppress single-phonon–emitter interactions up to 20 K, allowing the investigation of multi-phonon processes in the emitters. Our results represent an important step towards the realization of efficient phonon–emitter interfaces that can be used for quantum acoustodynamics and quantum phononic networks.