Variational Quantum Metrology with Loschmidt Echo

• URL: http://arxiv.org/abs/2211.12296v1
• Date: Tue, 22 Nov 2022 14:21:59 GMT
• Title: Variational Quantum Metrology with Loschmidt Echo
• Authors: Ran Liu, Ze Wu, Xiaodong Yang, Yuchen Li, Hui Zhou, Yuquan Chen, Haidong Yuan, Xinhua Peng, Jiangfeng Du
• Abstract summary: We propose a scalable scheme with a symmetrical variational quantum circuit which, same as the Loschmidt echo, consists of a forward and a backward evolution. We show that in this scheme the quantum Fisher information, which quantifies the precision limit, can be efficiently obtained from a measurement signal of the Loschmidt echo. We experimentally implement the scheme on an ensemble of 10-spin quantum processor and successfully achieves a precision near the theoretical limit which outperforms the standard quantum limit with 12.4 dB.
• Score: 20.002455345052702
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: By utilizing quantum mechanical effects, such as superposition and entanglement, quantum metrology promises higher precision than the classical strategies. It is, however, practically challenging to realize the quantum advantages. This is mainly due to the difficulties in engineering non-classical probe state and performing nontrivial measurement in practise, particularly with a large number of particles. Here we propose a scalable scheme with a symmetrical variational quantum circuit which, same as the Loschmidt echo, consists of a forward and a backward evolution. We show that in this scheme the quantum Fisher information, which quantifies the precision limit, can be efficiently obtained from a measurement signal of the Loschmidt echo. We experimentally implement the scheme on an ensemble of 10-spin quantum processor and successfully achieves a precision near the theoretical limit which outperforms the standard quantum limit with 12.4 dB. The scheme can be efficiently implemented on various noisy intermediate-scale quantum devices which provides a promising routine to demonstrate quantum advantages.

Related papers

• Benchmarking digital quantum simulations above hundreds of qubits using quantum critical dynamics [42.29248343585333]
  We benchmark quantum hardware and error mitigation techniques on up to 133 qubits. We show reliable control up to a two-qubit gate depth of 28, featuring a maximum of 1396 two-qubit gates. Results are transferable to applications such as Hamiltonian simulation, variational algorithms, optimization, or quantum machine learning.
  arXiv  Detail & Related papers  (2024-04-11T18:00:05Z)
• Power Characterization of Noisy Quantum Kernels [52.47151453259434]
  We show that noise may make quantum kernel methods to only have poor prediction capability, even when the generalization error is small. We provide a crucial warning to employ noisy quantum kernel methods for quantum computation.
  arXiv  Detail & Related papers  (2024-01-31T01:02:16Z)
• SAT-Based Quantum Circuit Adaptation [0.9784637657097822]
  Adapting a quantum circuit from a universal quantum gate set to the quantum gate set of a target hardware modality has a crucial impact on the fidelity and duration of the intended quantum computation. We develop a satisfiability modulo theories model that determines an optimized quantum circuit adaptation given a set of allowed substitutions and decompositions.
  arXiv  Detail & Related papers  (2023-01-27T14:09:29Z)
• Finite-round quantum error correction on symmetric quantum sensors [8.339831319589134]
  Heisenberg limit provides a quadratic improvement over the standard quantum limit. It remains elusive because of the inevitable presence of noise decohering quantum sensors. We side-step this no-go result by using an optimal finite number of rounds of quantum error correction.
  arXiv  Detail & Related papers  (2022-12-12T23:41:51Z)
• 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)
• Schr\"odinger-Heisenberg Variational Quantum Algorithms [1.9887498823918806]
  Recent breakthroughs have opened the possibility to intermediate-scale quantum computing with tens to hundreds of qubits. The extremely high accuracy needed to surpass classical computers poses a critical demand to the circuit depth. Here, we propose a paradigm of Schr"odinger-Heisenberg variational quantum algorithms to resolve this problem.
  arXiv  Detail & Related papers  (2021-12-15T04:53:01Z)
• Efficient criteria of quantumness for a large system of qubits [58.720142291102135]
  We discuss the dimensionless combinations of basic parameters of large, partially quantum coherent systems. Based on analytical and numerical calculations, we suggest one such number for a system of qubits undergoing adiabatic evolution.
  arXiv  Detail & Related papers  (2021-08-30T23:50:05Z)
• Quantum algorithms for quantum dynamics: A performance study on the spin-boson model [68.8204255655161]
  Quantum algorithms for quantum dynamics simulations are traditionally based on implementing a Trotter-approximation of the time-evolution operator. variational quantum algorithms have become an indispensable alternative, enabling small-scale simulations on present-day hardware. We show that, despite providing a clear reduction of quantum gate cost, the variational method in its current implementation is unlikely to lead to a quantum advantage.
  arXiv  Detail & Related papers  (2021-08-09T18:00:05Z)
• Noncyclic nonadiabatic holonomic quantum gates via shortcuts to adiabaticity [5.666193021459319]
  We propose a fast and robust scheme to construct high-fidelity holonomic quantum gates for universal quantum systems via shortcuts to adiabaticity. Our scheme is readily realizable in physical system currently pursued for implementation of quantum computation.
  arXiv  Detail & Related papers  (2021-05-28T15:23:24Z)
• Direct Quantum Communications in the Presence of Realistic Noisy Entanglement [69.25543534545538]
  We propose a novel quantum communication scheme relying on realistic noisy pre-shared entanglement. Our performance analysis shows that the proposed scheme offers competitive QBER, yield, and goodput.
  arXiv  Detail & Related papers  (2020-12-22T13:06:12Z)
• Boundaries of quantum supremacy via random circuit sampling [69.16452769334367]
  Google's recent quantum supremacy experiment heralded a transition point where quantum computing performed a computational task, random circuit sampling. We examine the constraints of the observed quantum runtime advantage in a larger number of qubits and gates.
  arXiv  Detail & Related papers  (2020-05-05T20:11:53Z)

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.