Quantum Pure State Tomography via Variational Hybrid Quantum-Classical Method

• URL: http://arxiv.org/abs/2001.05806v1
• Date: Thu, 16 Jan 2020 14:07:27 GMT
• Title: Quantum Pure State Tomography via Variational Hybrid Quantum-Classical Method
• Authors: Tao Xin, Xinfang Nie, Xiangyu Kong, Jingwei Wen, Dawei Lu, Jun Li
• Abstract summary: We introduce a self-learning tomographic scheme based on the variational hybrid quantum-classical method. Our scheme is further experimentally tested using techniques of a 4-qubit nuclear magnetic resonance.
• Score: 8.028037262377458
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: To obtain a complete description of a quantum system, one usually employs standard quantum state tomography, which however requires exponential number of measurements to perform and hence is impractical when the system's size grows large. In this work, we introduce a self-learning tomographic scheme based on the variational hybrid quantum-classical method. The key part of the scheme is a learning procedure, in which we learn a control sequence capable of driving the unknown target state coherently to a simple fiducial state, so that the target state can be directly reconstructed by applying the control sequence reversely. In this manner, the state tomography problem is converted to a state-to-state transfer problem. To solve the latter problem, we use the closed-loop learning control approach. Our scheme is further experimentally tested using techniques of a 4-qubit nuclear magnetic resonance. {Experimental results indicate that the proposed tomographic scheme can handle a broad class of states including entangled states in quantum information, as well as dynamical states of quantum many-body systems common to condensed matter physics.

Related papers

• Learning to Classify Quantum Phases of Matter with a Few Measurements [41.94295877935867]
  We study the identification of quantum phases of matter, at zero temperature, when only part of the phase diagram is known in advance. We show how to use our previous knowledge to construct an observable capable of classifying the phase even in the unknown region. An important application of our findings is the classification of the phases of matter obtained in quantum simulators.
  arXiv  Detail & Related papers  (2024-09-08T18:52:34Z)
• Second Law of Entanglement Manipulation with Entanglement Battery [41.94295877935867]
  A central question since the beginning of quantum information science is how two distant parties can convert one entangled state into another. It has been conjectured that entangled state transformations could be executed reversibly in an regime, mirroring the nature of Carnot cycles in classical thermodynamics. We investigate the concept of an entanglement battery, an auxiliary quantum system that facilitates quantum state transformations without a net loss of entanglement.
  arXiv  Detail & Related papers  (2024-05-17T07:55:04Z)
• Quantum state tomography with disentanglement algorithm [0.0]
  We use variational quantum circuits to disentangle the quantum state to a product of computational zero states. Inverse evolution of the zero states reconstructs the quantum state up to an overall phase. Our method is universal and imposes no specific ansatz or constrain on the quantum state.
  arXiv  Detail & Related papers  (2023-10-10T03:11:12Z)
• Quantum process tomography of continuous-variable gates using coherent states [49.299443295581064]
  We demonstrate the use of coherent-state quantum process tomography (csQPT) for a bosonic-mode superconducting circuit. We show results for this method by characterizing a logical quantum gate constructed using displacement and SNAP operations on an encoded qubit.
  arXiv  Detail & Related papers  (2023-03-02T18:08:08Z)
• Quantum state tomography with tensor train cross approximation [84.59270977313619]
  We show that full quantum state tomography can be performed for such a state with a minimal number of measurement settings. Our method requires exponentially fewer state copies than the best known tomography method for unstructured states and local measurements.
  arXiv  Detail & Related papers  (2022-07-13T17:56:28Z)
• Single-Qubit Reaped Quantum State Tomography [0.0]
  We propose a new scheme of quantum state tomography that requires the measurement of only three observables. The wavefunction of the system is "reaped" onto the pointer upon the measurement of the system. We also developed an efficient and scalable iterative maximum likelihood algorithm to estimate states from statistically incomplete data.
  arXiv  Detail & Related papers  (2022-06-20T03:57:49Z)
• Variational Approach to Quantum State Tomography based on Maximal Entropy Formalism [3.6344381605841187]
  We employ the maximal entropy formalism to construct the least biased mixed quantum state that is consistent with the given set of expectation values. We employ a parameterized quantum circuit and a hybrid quantum-classical variational algorithm to obtain such a target state making our recipe easily implementable on a near-term quantum device.
  arXiv  Detail & Related papers  (2022-06-06T01:16:22Z)
• Canonically consistent quantum master equation [68.8204255655161]
  We put forth a new class of quantum master equations that correctly reproduce the state of an open quantum system beyond the infinitesimally weak system-bath coupling limit. Our method is based on incorporating the knowledge of the reduced steady state into its dynamics.
  arXiv  Detail & Related papers  (2022-05-25T15:22:52Z)
• 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)
• Probing Topological Spin Liquids on a Programmable Quantum Simulator [40.96261204117952]
  We use a 219-atom programmable quantum simulator to probe quantum spin liquid states. In our approach, arrays of atoms are placed on the links of a kagome lattice and evolution under Rydberg blockade creates frustrated quantum states. The onset of a quantum spin liquid phase of the paradigmatic toric code type is detected by evaluating topological string operators.
  arXiv  Detail & Related papers  (2021-04-09T00:18:12Z)
• Reconstructing quantum states with quantum reservoir networks [4.724825031148412]
  We introduce a quantum state tomography platform based on the framework of reservoir computing. It forms a quantum neural network, and operates as a comprehensive device for reconstructing an arbitrary quantum state.
  arXiv  Detail & Related papers  (2020-08-14T14:01:55Z)

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.