The randomized measurement toolbox

• URL: http://arxiv.org/abs/2203.11374v1
• Date: Mon, 21 Mar 2022 22:33:18 GMT
• Title: The randomized measurement toolbox
• Authors: Andreas Elben, Steven T. Flammia, Hsin-Yuan Huang, Richard Kueng, John Preskill, Beno\^it Vermersch, Peter Zoller
• Abstract summary: We review recently developed protocols for probing the properties of complex many-qubit systems. In all these protocols, a quantum state is repeatedly prepared and measured in a randomly chosen basis. We discuss a range of use cases that have already been realized in quantum devices.
• Score: 3.2095357952052854
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Increasingly sophisticated 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 their power, but also makes them difficult to control precisely or characterize accurately using measured classical data. We review recently developed protocols for probing the properties of complex many-qubit systems using measurement schemes that are practical using today's quantum platforms. In all 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 employed 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 use cases that have already been realized in quantum devices, including Hamiltonian simulation tasks, probes of quantum chaos, measurements of nonlocal 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.

Related papers

• Efficient Learning for Linear Properties of Bounded-Gate Quantum Circuits [63.733312560668274]
  Given a quantum circuit containing d tunable RZ gates and G-d Clifford gates, can a learner perform purely classical inference to efficiently predict its linear properties? We prove that the sample complexity scaling linearly in d is necessary and sufficient to achieve a small prediction error, while the corresponding computational complexity may scale exponentially in d. We devise a kernel-based learning model capable of trading off prediction error and computational complexity, transitioning from exponential to scaling in many practical settings.
  arXiv  Detail & Related papers  (2024-08-22T08:21:28Z)
• Analysing quantum systems with randomised measurements [0.4179230671838898]
  We present the advancements made in utilising randomised measurements in various scenarios of quantum information science. We describe how to detect and characterise different forms of entanglement, including genuine multipartite entanglement and bound entanglement. We also present an overview on the estimation of non-linear functions of quantum states and shadow tomography from randomised measurements.
  arXiv  Detail & Related papers  (2023-07-03T18:00:01Z)
• Statistical learning on randomized data to verify quantum state k-designs [0.0]
  Random ensembles of pure states have proven to be extremely important in various aspects of quantum physics. generating a fully random ensemble is experimentally challenging but approximations are just as useful. verifying their degree of randomness can be an expensive task, similar to performing full quantum state tomography on many-body systems.
  arXiv  Detail & Related papers  (2023-05-02T14:46:28Z)
• Measuring Arbitrary Physical Properties in Analog Quantum Simulation [0.5999777817331317]
  A central challenge in analog quantum simulation is to characterize desirable physical properties of quantum states produced in experiments. We propose and analyze a scalable protocol that leverages the ergodic nature of generic quantum dynamics. Our protocol excitingly promises to overcome limited controllability and, thus, enhance the versatility and utility of near-term quantum technologies.
  arXiv  Detail & Related papers  (2022-12-05T19:00:01Z)
• Anticipative measurements in hybrid quantum-classical computation [68.8204255655161]
  We present an approach where the quantum computation is supplemented by a classical result. Taking advantage of its anticipation also leads to a new type of quantum measurements, which we call anticipative. In an anticipative quantum measurement the combination of the results from classical and quantum computations happens only in the end.
  arXiv  Detail & Related papers  (2022-09-12T15:47:44Z)
• Benchmarking Quantum Simulators using Ergodic Quantum Dynamics [4.2392660892009255]
  We analyze a sample-efficient protocol to estimate the fidelity between an experimentally prepared state and an ideal state. We numerically demonstrate our protocol for a variety of quantum simulator platforms.
  arXiv  Detail & Related papers  (2022-05-24T17:18:18Z)
• Interactive Protocols for Classically-Verifiable Quantum Advantage [46.093185827838035]
  "Interactions" between a prover and a verifier can bridge the gap between verifiability and implementation. We demonstrate the first implementation of an interactive quantum advantage protocol, using an ion trap quantum computer.
  arXiv  Detail & Related papers  (2021-12-09T19:00:00Z)
• Characterizing quantum instruments: from non-demolition measurements to quantum error correction [48.43720700248091]
  In quantum information processing quantum operations are often processed alongside measurements which result in classical data. Non-unitary dynamical processes can take place on the system, for which common quantum channel descriptions fail to describe the time evolution. Quantum measurements are correctly treated by means of so-called quantum instruments capturing both classical outputs and post-measurement quantum states.
  arXiv  Detail & Related papers  (2021-10-13T18:00:13Z)
• Certification of quantum states with hidden structure of their bitstrings [0.0]
  We propose a numerically cheap procedure to describe and distinguish quantum states. We show that it is enough to characterize quantum states with different structure of entanglement. Our approach can be employed to detect phase transitions of different nature in many-body quantum magnetic systems.
  arXiv  Detail & Related papers  (2021-07-21T06:22:35Z)
• Preparing random states and benchmarking with many-body quantum chaos [48.044162981804526]
  We show how to predict and experimentally observe the emergence of random state ensembles naturally under time-independent Hamiltonian dynamics. The observed random ensembles emerge from projective measurements and are intimately linked to universal correlations built up between subsystems of a larger quantum system. Our work has implications for understanding randomness in quantum dynamics, and enables applications of this concept in a wider context.
  arXiv  Detail & Related papers  (2021-03-05T08:32:43Z)
• Information Scrambling in Computationally Complex Quantum Circuits [56.22772134614514]
  We experimentally investigate the dynamics of quantum scrambling on a 53-qubit quantum processor. We show that while operator spreading is captured by an efficient classical model, operator entanglement requires exponentially scaled computational resources to simulate.
  arXiv  Detail & Related papers  (2021-01-21T22:18:49Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.