This theme focuses on leveraging the unprecedented characterization and control that have been achieved through modern nanoscience to develop deeper understandings and new experimental platforms for quantum information science (QIS). We have a three-pronged approach to impact QIS: qubit discovery, deterministic placement and characterization of qubits, and to manipulate and control quantum coherence.
The first prong, qubit discovery, deals with the discovery of solid-state systems that allow us to create coherent quantum information for sensing, computing or communication. Single-photon emitters and optically active spin systems have emerged as powerful platforms for this because they can be initialized, manipulated, and read out remotely with light; they can store quantum information in the long-lived spin degree-of-freedom; and they can serve as sensitive sensors at nanometer length scales.
These systems can take the physical form of defects or dopants in a host matrix or of semiconducting particles, which are nanostructured for quantum confinement; either way, these systems are intrinsically nanoscale in nature, and their development will benefit immensely from the strategic deployment of nanoscience experimental and theoretical methodologies, expertise, and instrumentation.
These studies include the fundamentals of spin, single-photon, phonon and magnon dynamics; sub-wavelength light localization; topological materials; and the creation and manipulation of dopants and defects in materials for quantum coherence and entanglement. These phenomena comprise the underlying science for any practical quantum system (computing, sensing or communication) and the building blocks for qubit transduction schemes, quantum memories, and information transport.
The second prong deals with placing and characterizing qubits, such as quantum defects. The ability to place qubits precisely (at the nanometer level) allows researchers to initiate and control the entanglement—the quantum phenomenon that drives a great portion of the promise of QIS—between qubits. This is the basis for QIS’s extraordinary computing power, the secure nature of quantum networks, and the precision of nanoscale quantum sensors.
The degree of entanglement between particles relies on many details, such as relative energy levels, relative orientations of neighboring qubits, and the timescale of quantum coherence (such as spin coherence) for each particle. Thus, extensive characterization to optimize qubit performance and the ability to place qubits precisely are both needed to realize the promise of QIS.
The third prong is to achieve, manipulate, and control quantum coherence. This requires a pathway to use an external input, such as light, that can be coupled to the quantum coherent excitations. We are developing advanced means to increase the degree of coupling between photons and quantum excitation and provide a pathway to external control of quantum coherence.
This is also the means to convert, or “transduce,” quantum information from a qubit in a quantum material to photons, and thereby transport quantum information via a network. Such an ability for transduction is critical for the development of quantum networks of the future.
The three-pronged approach described above—through our own science and the user science that CNM enables—will further the fundamental science leading to the creation, storage, manipulation, and entanglement of quanta of information using these nanoscale solid-state systems.