The randomized measurement toolbox
Abstract
Programmable quantum simulators and quantum computers are opening unprecedented opportunities for exploring and exploiting the properties of highly entangled complex quantum systems. The complexity of large quantum systems is the source of computational power but also makes them difficult to control precisely or characterize accurately using measured classical data. We review protocols for probing the properties of complex many-qubit systems using measurement schemes that are practical using today's quantum platforms. In these protocols, a quantum state is repeatedly prepared and measured in a randomly chosen basis; then a classical computer processes the measurement outcomes to estimate the desired property. The randomization of the measurement procedure has distinct advantages. For example, a single data set can be used multiple times to pursue a variety of applications, and imperfections in the measurements are mapped to a simplified noise model that can more easily be mitigated. We discuss a range of cases that have already been realized in quantum devices, including Hamiltonian simulation tasks, probes of quantum chaos, measurements of non-local order parameters, and comparison of quantum states produced in distantly separated laboratories. By providing a workable method for translating a complex quantum state into a succinct classical representation that preserves a rich variety of relevant physical properties, the randomized measurement toolbox strengthens our ability to grasp and control the quantum world.
Additional Information
© 2023 Nature Publishing Group. A.E. acknowledges funding by the German National Academy of Sciences Leopoldina under grant no. LPDS 2021-02 and by the Walter Burke Institute for Theoretical Physics at Caltech. J.P. acknowledges funding from the US Department of Energy Office of Science, Office of Advanced Scientific Computing Research (DE-NA0003525, DE-SC0020290), and the National Science Foundation (NSF) (PHY-1733907). The Institute for Quantum Information and Matter is an NSF Physics Frontiers Center. B.V. acknowledges funding from the French National Research Agency (ANR-20-CE47-0005, JCJC project QRand) and from the Austrian Science Foundation (FWF, P 32597 N). P.Z. acknowledges support by the US Air Force Office of Scientific Research (AFOSR) via IOE grant no. FA9550-19-1-7044 LASCEM, by the European Union's Horizon 2020 research and innovation programme under grant agreement no. 817482 (PASQuanS), and by the Simons Collaboration on Ultra-Quantum Matter, which is a grant from the Simons Foundation (651440). The authors contributed equally to all aspects of the article. The authors declare no competing interests.Additional details
- Eprint ID
- 119561
- Resolver ID
- CaltechAUTHORS:20230227-88449200.49
- LPDS 2021-02
- Deutsche Akademie der Naturforscher Leopoldina
- Walter Burke Institute for Theoretical Physics, Caltech
- DE-NA0003525
- Department of Energy (DOE)
- DE-SC0020290
- Department of Energy (DOE)
- PHY-1733907
- NSF
- ANR-20-CE47-0005
- Agence Nationale pour la Recherche (ANR)
- P 32597 N
- FWF Der Wissenschaftsfonds
- FA9550-19-1-7044
- Air Force Office of Scientific Research (AFOSR)
- 817482
- European Research Council (ERC)
- 651440
- Simons Foundation
- Created
-
2023-05-01Created from EPrint's datestamp field
- Updated
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2023-05-01Created from EPrint's last_modified field
- Caltech groups
- Institute for Quantum Information and Matter, Walter Burke Institute for Theoretical Physics, AWS Center for Quantum Computing