Direct tomography of quantum states and processes via weak measurements of Pauli spin operators on an NMR quantum processor
arXiv:2303.06892 · doi:10.1140/epjd/s10053-023-00791-6
Abstract
In this paper, we present an efficient weak measurement-based scheme for direct quantum state tomography (DQST) and direct quantum process tomography (DQPT), and experimentally implement it on an NMR ensemble quantum information processor without involving any projective measurements. We develop a generalized quantum circuit that enables us to directly measure selected elements of the density matrix and process matrix which characterize unknown quantum states and processes, respectively. This generalized quantum circuit uses the scalar J-coupling to control the interaction strength between the system qubits and the metre qubit. We experimentally implement these weak measurement-based DQST and DQPT protocols and use them to accurately characterize several two-qubit quantum states and single-qubit quantum processes. An extra qubit is used as a metre qubit to implement the DQST protocol, while for the DQPT protocol, two extra qubits (one as a metre qubit and the other as an ancilla qubit) are used.
arXiv comment10 pages, 5 figures
References in corpus (26)
- Direct Measurement of the Quantum Wavefunction
- Nuclear magnetic resonance spectroscopy: An experimentally accessible paradigm for quantum computing
- Direct measurement of general quantum states using weak measurement
- Direct observation of Hardy's paradox by joint weak measurement with an entangled photon pair
- Precision metrology using weak measurements
- Observation of a quantum Cheshire Cat in a matter wave interferometer experiment
- Partial-measurement back-action and non-classical weak values in a superconducting circuit
- Direct measurement of the density matrix of a quantum system
- Manipulating a qubit through the backaction of sequential partial measurements and real-time feedback
- Protecting quantum states from decoherence of finite temperature using weak measurement
- Measuring incompatible observables of a single photon
- Experiment Investigating the Connection between Weak Values and Contextuality
- Experimental realization of post-selected weak measurements on an NMR quantum processor
- Experimental demonstration of selective quantum process tomography on an NMR quantum information processor
- Anomalous Weak Values and the Violation of a Multiple-measurement Leggett-Garg Inequality
- Constructing valid density matrices on an NMR quantum information processor via maximum likelihood estimation
- Experimental Classification of Entanglement in Arbitrary Three-Qubit States on an NMR Quantum Information Processor
- Estimation of quantum states by weak and projective measurements
- Direct Characterization of Quantum Measurements using Weak Values
- Minimum Disturbance Measurement without Post-Selection
- Implementing efficient selective quantum process tomography of superconducting quantum gates on the IBM quantum processor
- Do weak values capture the complete truth about the past of a quantum particle?
- Selective and Efficient Quantum Process Tomography in Arbitrary Finite Dimension
- Direct measurement of density-matrix elements using a phase-shifting technique Tianfeng
- Classification and measurement of multipartite entanglement by reconstruction of correlation tensors on an NMR quantum processor
- Efficient experimental characterization of quantum processes via compressed sensing on an NMR quantum processor