Abstract
A future quantum internet will enable fundamentally new applications such as secure
communication, distributed quantum computing, and quantum-enhanced metrology and
sensing [1]. Recently, a rudimentary quantum network hosting multiple nodes has been
demonstrated [2]. However, challenges in scaling up this network motivate the further
development of different qubit platforms, such as trapped ions and atoms, and solid-
state emitters.
Qubits based on single rare-earth ions (REIs) are promising candidates; they exhibit
good qubit and optical properties due to their internal atomic structure. Auxiliary qubits
are offered in the form of nuclear spins present in the host material. In the Faraon lab,
we have recently established distributed entanglement of two and subsequently three
qubits, across two nodes [3].
In this seminar, I will discuss ongoing projects: extending the auxiliary qubit control and
understanding the noise processes limiting the REI qubit coherence. Additionally, I will
outline the future research directions for my lab in Delft: exploring different host
materials, developing robust and scalable nanofabrication methods for more elaborate
REI-based devices, and investigating two-REI-qubit interactions.
Biography
Dr. Sophie Hermans is an incoming Assistant Professor/Group leader at the research institute
QuTech, at the Delft University of Technology in the Netherlands. Starting in May 2025, her
research team will focus on rare-earth ions doped in host materials for quantum networking
applications.
Currently, Hermans is a postdoctoral scholar in the group of Prof. Faraon at the California
Institute of Technology (Caltech). She works on utilizing single ytterbium ions doped in host
crystals for quantum networks and quantum sensing purposes.
Before moving to the United States, Hermans received her PhD at the Delft University of
Technology in the Netherlands. In the team of Prof. Hanson, she developed the world’s first
multi-node quantum network, based on nitrogen-vacancy centers in diamond. Additionally, she
worked on quantum frequency conversion of single photons from the visible to the telecom
regime.
Hermans was elected one of the Faces of Science by the Dutch Royal Academy of Science and
serves as an ambassador of science through outreach and science communication. Upon
joining Caltech, she was awarded the AWS Quantum Fellowship. In 2024, Hermans received
the Delft Technology Fellowship to support the start of her research program.
[1 ] S. Wehner, D. Elkouss, and R. Hanson, “Quantum internet: A vision for the road ahead,”
Science, vol. 362, no. 6412 (2018)
[2] M. Pompili, S. L. N. Hermans, S. Baier, et al., “Realization of a multinode quantum network of
remote solid-state qubits,” Science, vol. 372, no. 6539, pp. 259–264 (2021)
[3] A. Ruskuc, C.-J. Wu, E. Green, S. L. N. Hermans, J. Choi, and A. Faraon, “Scalable
Multipartite Entanglement of Remote Rare-earth Ion Qubits,” arXiv:2402.16224 (2024)