Overcomplete quantum tomography of a path-entangled two-photon state
arXiv:1707.07837 · doi:10.1103/PhysRevA.99.022312
Abstract
Path-entangled N-photon states can be obtained through the coalescence of indistinguishable photons inside linear networks. They are key resources for quantum enhanced metrology, quantum imaging, as well as quantum computation based on quantum walks. However, the quantum tomography of path-entangled indistinguishable photons is still in its infancy as it requires multiple phase estimations increasing rapidly with N. Here, we propose and implement a method to measure the quantum tomography of path-entangled two-photon states. A two-photon state is generated through the Hong-Ou-Mandel interference of highly indistinguishable single photons emitted by a semiconductor quantum dot-cavity device. To access both the populations and the coherences of the path-encoded density matrix, we introduce an ancilla spatial mode and perform photon correlations as a function of a single phase in a split Mach-Zehnder interferometer. We discuss the accuracy of standard quantum tomography techniques and show that an overcomplete data set can reveal spatial coherences that could be otherwise hidden due to limited or noisy statistics. Finally, we extend our analysis to extract the truly indistinguishable part of the density matrix, which allows us to identify the main origin for the imperfect fidelity to the maximally entangled state.
arXiv comment7 pages, 5 figures
References in corpus (38)
- On the Measurement of Qubits
- Quantum Interferometric Optical Lithography: Exploiting Entanglement to Beat The Diffraction Limit
- Near optimal single photon sources in the solid state
- Quantum Optical Metrology -- The Lowdown on High-N00N States
- Super-resolving phase measurements with a multi-photon entangled state
- Beating the Standard Quantum Limit with Four Entangled Photons
- Experimental boson sampling in arbitrary integrated photonic circuits
- Two-photon diffraction and quantum lithography
- Biological measurement beyond the quantum limit
- Non-maximally entangled states: production, characterization and utilization
- Imaging with a small number of photons
- Universal computation by multi-particle quantum walk
- Mach-Zehnder Interferometry at the Heisenberg Limit with coherent and squeezed-vacuum light
- Qudit Quantum State Tomography
- Generating, manipulating and measuring entanglement and mixture with a reconfigurable photonic circuit
- Qubit entanglement on a silicon photonic chip
- Three-photon bosonic coalescence in an integrated tritter
- Entanglement-enhanced probing of a delicate material system
- Two-particle quantum walks applied to the graph isomorphism problem
- Scalable performance in solid-state single-photon sources
- Homodyne tomography characterization and nonlocality of a dual-mode optical qubit
- Generation of Large Number-Path Entanglement Using Linear Optics and Feed-Forward
- Generalized multi-photon quantum interference
- Reducing phonon-induced decoherence in solid-state single-photon sources with cavity quantum electrodynamics
- High photon number path entanglement in the interference of spontaneously downconverted photon pairs with coherent laser light
- Efficient Quantum Walk on a Quantum Processor
- Creation of maximally entangled photon-number states using optical fiber multiports
- Experimental tomography of NOON states with large photon numbers
- Cavity-enhanced coherent light scattering from a quantum dot
- Loss-tolerant quantum enhanced metrology and state engineering via the reverse Hong-Ou-Mandel effect
- Witnessing trustworthy single-photon entanglement with local homodyne measurements
- State Tomography: Hidden Differences
- Revealing Genuine Optical-Path Entanglement
- Measuring arbitrary-order coherences: Tomography of single-mode multiphoton polarization-entangled states
- Heralded creation of photonic qudits from parametric down conversion using linear optics
- Verifying the quantumness of bipartite correlations
- NOON states from cavity-enhanced down-conversion: High quality and super-resolution
- Witnessing single-photon entanglement with local homodyne measurements: analytical bounds and robustness to losses