Content

Within the seminar Superconducting Quantum Circuits, students present state-of-the-art developments in modern quantum technology with superconducting quantum circuits. In this field, funamental research in academia has meanwhile triggered highly dynamical activities from established large corporations (Google, IBM, Intel etc.) and ambitious startups (Rigetti, IQM, HQS etc.). In particular, superconducting quantum circuits belong to the few prime candidates for a scalable quantum computer.

Time/Place

12:00 - 14:00h, WMI-Seminarroom, room 143

Schedule

List of open topics for seminar talks in SS 2024:

Quantum Computing:

1. Logical quantum processor based on reconfigurable atom arrays    Nature    Lukin (MIT),  https://www.nature.com/articles/s41586-023-06927-3
2. Encoding a magic state with beyond break-even fidelity, Nature, IBM,    https://www.nature.com/articles/s41586-023-06846-3
3. Efficient long-range entanglement using dynamic circuits (IBM),    https://arxiv.org/abs/2308.13065
4. Beating the break-even point with a discrete-variable-encoded logical qubit (Yu),    https://doi.org/10.1038/s41586-023-05784-4

Superconducting Circuits

1. Generation of genuine entanglement up to 51 superconducting qubits (Pan, Hefei),    https://www.nature.com/articles/s41586-023-06195-1
2. Microwave Photon-Number Amplification   (Hofheinz, Grenoble/Sherbrooke),    https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.011011,
3. Dual-rail encoding with superconducting cavities (Schoelkopf, Yale),    https://www.pnas.org/doi/abs/10.1073/pnas.2221736120
4. High-Fidelity, Frequency-Flexible Two-Qubit Fluxonium Gates with a Transmon Coupler (Oliver, MIT),    https://journals.aps.org/prx/abstract/10.1103/PhysRevX.13.031035
5. Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier (Bylander, Chalmers),    https://www.nature.com/articles/s41534-023-00689-6
6. Two-level system hyperpolarization using a quantum Szilard engine (Pop, KIT),  https://www.nature.com/articles/s41567-023-02082-8
7. Realizing a deep reinforcement learning agent for real-time quantum feedback   (Marquadt, Wallraff, Eichler, ETH),    https://www.nature.com/articles/s41467-023-42901-3
8. Cloaking a qubit in a cavity  (Huard/ Blais , Lyon/Sherbrooke),     https://www.nature.com/articles/s41467-023-42060-5
9. Bidirectional Multiphoton Communication between Remote Superconducting Nodes (Cleland, Chicago),    https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.047001
10. Optimizing Resource Efficiencies for Scalable Full-Stack Quantum Computers (Auffeves), https://journals.aps.org/prxquantum/abstract/10.1103/PRXQuantum.4.040319?utm_source=email&utm_medium=email&utm_campaign=prxquantum-alert
11. On-demand directional microwave photon emission using waveguide quantum electrodynamics (Oliver, MIT), https://www.nature.com/articles/s41567-022-01869-5
12. Millisecond Coherence in a Superconducting Qubit  (Manucharyan),     https://doi.org/10.1103/PhysRevLett.130.267001
13. Quantum Simulation of Topological Zero Modes on a 41-Qubit Superconducting Processor (Heng Fan, Hefei), https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.080401

Quantum Sensing

1. Correlation Spectroscopy with Multiqubit-Enhanced Phase Estimation (Roos, Blatt , Innsbruck), https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.011033
2. High-sensitivity AC-charge detection with a MHz-frequency fluxonium qubit (Deleglise, CNRS), https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.011007
3. Quantum advantage in microwave quantum radar (Huard),    https://doi.org/10.1038/s41567-023-02113-4

Hybrid Quantum Systems

1. Quantum-enabled millimetre wave to optical transduction using neutral atoms (Schuster, Simon, Stanford), https://www.nature.com/articles/s41586-023-05740-2
2. Single electron-spin-resonance detection by microwave photon counting (Flurin, Bertet, CEA Saclay)    https://www.nature.com/articles/s41586-023-06097-2

Theory

1. Charging Effects in the Inductively Shunted Josephson Junction (J. Koch, Yale), https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.103.217004

2. Efficient high-fidelity flying qubit shaping (Burkard, Konstanz), https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.6.013150

3. Multimode-cavity picture of non-Markovian waveguide QED (Ciccarello, Palermo), https://arxiv.org/abs/2403.07110

4. Reminiscence of Classical Chaos in Driven Transmons (Blais, Sherbrooke), https://journals.aps.org/prxquantum/abstract/10.1103/PRXQuantum.4.020312

Topical directions of the seminar:

• Foundations and applications of superconducting quantum circuits in quantum computing, quantum simulation, quantum communication, quantum sensing, and quantum metrology.
• Superconducting quantum technology: Resonators, waveguides, quantum bits, couplers, quantum-limited amplifiers, quantum processors, quantum error correction etc.
• State-of-the-art fabrication and measurement tachniques for superconducting quantum circuits.
• Investigation of the fundamental light-matter interaction "on a chip" using superconducting quantum circuits.
• Quantum information theoretical concepts: Entanglement, quantum gates, quantum algorithms, quantum memories, quantum measurements etc.
• The coupling of nanomechanical systems and spin ensembles to superconducting circuits.
• Challenges: longer quantum coherence, higher gate fidelities, scalability to a large number of qubits etc.
• Latest developments on the strive towards quantum advantages over conventional technology
• Propagating quantum microwaves emitted by superconducting circuits: quantum ressources, quantum microwave communication, quantum radar

You will be supported in the preparation of your talks from the research groups on superconducting quantum circuits, propagating quantum microwaves, and nanomechanics at the Walther-Meißner-Institute.

Learning Outcome:

After the successful completion of the module the students are able

• To prepare presentation slides on a scientific topic and to clearly present a topical research field within a scientific talk.
• To discuss on a state-of-the-art research field in a scientific way.
• To analyze and assess the latest development in quantum scinece and technology with superconducting circuits.
• To understand and explain the foundations of superconducting quantum systems and technology.
• To understand the foundations and the state of the art in quantum computing, quantum simulation, quantum communication, quantum sensing, and quantum metrology with supercondcuting circuits
• To understand the foundations and the state of the art in nanomechnical systems and spin ensembles

Preconditions:

Basic knowledge of condensed matter physics, foundations of quantum mechanics