We propose a quantum diffraction imaging technique whereby one photon of an entangled pair is diffracted off a sample and detected in coincidence with its twin. The image is obtained by scanning the photon that did not interact with matter. We show that when a dynamical quantum system interacts with an external field, the phase information is imprinted in the state of the field in a detectable way. The contribution to the signal from photons that interact with the sample scales as ∝ I p 1 / 2 , where I p is the source intensity, compared with ∝ I p of classical diffraction. This makes imaging with weak fields possible, providing high signaltonoise ratio, avoiding damage to delicate samples. A Schmidt decomposition of the state of the field can be used for image enhancement by reweighting the Schmidt modes contributions.
Probing dynamical symmetry breaking using quantumentangled photons
We present an input/output analysis of photoncorrelation experiments whereby a quantum mechanically entangled biphoton state interacts with a material sample placed in one arm of a Hong–Ou–Mandel apparatus. We show that the output signal contains detailed information about subsequent entanglement with the microscopic quantum states in the sample. In particular, we apply the method to an ensemble of emitters interacting with a common photon mode within the opensystem Dicke model. Our results indicate considerable dynamical information concerning spontaneous symmetry breaking can be revealed with such an experimental system.
 Publication Date:
 NSFPAR ID:
 10061097
 Journal Name:
 Quantum science and technology
 Volume:
 3
 Page Range or eLocationID:
 015003
 ISSN:
 23649054
 Sponsoring Org:
 National Science Foundation
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