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May 24, 2024
Speaker: András Gyenis (University of Colorado, Boulder | US)
Host: Johannes Fink / Farid Hassani
To unlock the potential of quantum computers, one of the key challenges that the field has to overcome is to preserve the coherence of a quantum superposition over extended times. Besides implementing quantum error correction schemes, a complementary approach to prolong the coherence of quantum processors is to develop qubits that are intrinsically protected against decoherence. In this talk, first, we introduce the requirement for intrinsic error protection [1] while highlighting the importance of novel nonlinear elements, including high-transmission Josephson junctions [2] and quantum phase slip elements. Then, we present a universal method to quantize circuits containing both Josephson junctions and quantum phase slip elements [3]. Relying on the connection between symplectic geometry, graph theory, and circuit theory, we describe a Hamiltonian formulation and quantization of non-dissipative electrodynamic circuits. In the second part of the talk, we present experimental results on how to use disordered superconductors to build superconducting qubits with protection against information loss. In particular, we focus on elements built from disordered WSi which has shown excellent properties in single-photon detectors.
[1] PRX Quantum 2, 030101 (2021)
[2] PRX Quantum 3, 030303 (2022)
[3] PRX Quantum 5, 020309 (2024)