Quantifying the presence of a neutron in the paths of an interferometer
- URL: http://arxiv.org/abs/2202.00272v1
- Date: Tue, 1 Feb 2022 08:21:54 GMT
- Title: Quantifying the presence of a neutron in the paths of an interferometer
- Authors: Hartmut Lemmel, Niels Geerits, Armin Danner, Yuji Hasegawa, Holger F.
Hofmann, Stephan Sponar
- Abstract summary: We experimentally investigate the possibility that an individual neutron moving through a two-path interferometer may actually be physically distributed between the two paths.
Results show that individual particles experience a specific fraction of the magnetic field applied in one of the paths, indicating that a fraction or even a multiple of the particle was present in the path before the interference of the two paths was registered.
- Score: 1.4680035572775534
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: It is commonly assumed that no accurate experimental information can be
obtained on the path taken by a particle when quantum interference between the
paths is observed. However, recent progress in the measurement and control of
quantum systems may provide the missing information by circumventing the
conventional uncertainty limits. Here, we experimentally investigate the
possibility that an individual neutron moving through a two-path interferometer
may actually be physically distributed between the two paths. For this purpose,
it is important to distinguish between the probability of finding the complete
particle in one of the paths and the distribution of an individual particle
over both paths. We accomplish this distinction by applying a magnetic field in
only one of the paths and observing the exact value of its effect on the
neutron spin in the two output ports of the interferometer. The results show
that individual particles experience a specific fraction of the magnetic field
applied in one of the paths, indicating that a fraction or even a multiple of
the particle was present in the path before the interference of the two paths
was registered. The obtained path presence equals the weak value of the path
projector and is not a statistical average but applies to every individual
neutron, verified by the recently introduced method of feedback compensation.
Related papers
- Threshold in quantum correlated interference for a particle interacting with two scatterers [0.0]
A measurement of this threshold can verify quantum correlations in many-body systems.
The decoherence of a mesoscopic scatterer is determined by this threshold without it having to traverse slits or beamsplitters.
arXiv Detail & Related papers (2024-08-14T11:34:34Z) - Breakdown of Measurement-Induced Phase Transitions Under Information Loss [39.36827689390718]
A quantum-many body system can feature measurement-induced phase transitions (MIPTs)
MIPTs cannot be revealed through ensemble-averaged observables, but it requires the ability to discriminate each trajectory separately.
We explore the fate of MIPTs under an observer's reduced ability to discriminate each measurement outcome.
arXiv Detail & Related papers (2024-07-18T18:10:52Z) - Counterfactuality, back-action, and information gain in multi-path interferometers [0.0]
We identify the advantage of quantum counterfactual protocols over classical counterfactual protocols.
A negative Kirkwood-Dirac term between a path and an output port indicates that inserting the absorber into that path will have a focussing effect.
We show that the magnitude of quantum counterfactual effects cannot be explained by a simple removal of the absorbed particles.
arXiv Detail & Related papers (2024-04-25T10:03:04Z) - Entanglement-induced collective many-body interference [62.22849132943891]
We propose an interferometric setting through which N-particle interference can be observed, while any interference of lower orders is strictly suppressed.
We experimentally demonstrate this effect in a four-photon interferometer, where the interference is nonlocal, in principle.
A joint detection of all four photons identifies a high-visibility interference pattern varying as a function of their collective four-particle phase, a genuine four-body property.
arXiv Detail & Related papers (2023-10-12T18:00:02Z) - Unambiguous joint detection of spatially separated properties of a
single photon in the two arms of an interferometer [0.0]
The quantum superposition principle implies that a particle entering an interferometer evolves by simultaneously taking both arms.
For a fixed state measured at the output port, certain particle properties can be associated with only one or the other path.
We report observation of the spatial and polarization degrees of freedom of a single photon in the two arms of an interferometer.
arXiv Detail & Related papers (2022-01-27T10:23:16Z) - Measurement-dependent erasure of distinguishability for the observation
of interference in an unbalanced SU(1,1) interferometer [3.2646353020000687]
Quantum interference can disappear with the mere possibility of distinguishability without performing the act.
We create such distinguishability in an unbalanced SU (1,1) interferometer and observe no interference in the direct photodetection of the outputs.
Here, we report a method of homodyne detection that can also recover interference effect.
arXiv Detail & Related papers (2021-09-22T08:39:26Z) - Quantum error as an emergent magnetic field [16.533265279392772]
We investigate the effect of quantum errors on a monitored Brownian Sachdev-Ye-Kitaev (SYK) model.
Errors describe the loss of information about the measurement outcomes and are applied during the non-unitary evolution or at the end of the evolution.
arXiv Detail & Related papers (2021-06-17T16:24:58Z) - Observation-dependent suppression and enhancement of two-photon
coincidences by tailored losses [68.8204255655161]
Hong-Ou-Mandel (HOM) effect can lead to a perfect suppression of two-particle coincidences between the output ports of a balanced beam splitter.
In this work, we demonstrate experimentally that the two-particle coincidence statistics of two bosons can instead be seamlessly tuned to substantial enhancement.
Our findings reveal a new approach to harnessing non-Hermitian settings for the manipulation of multi-particle quantum states.
arXiv Detail & Related papers (2021-05-12T06:47:35Z) - Detectable Signature of Quantum Friction on a Sliding Particle in Vacuum [58.720142291102135]
We show traces of quantum friction in the degradation of the quantum coherence of a particle.
We propose to use the accumulated geometric phase acquired by a particle as a quantum friction sensor.
The experimentally viable scheme presented can spark renewed optimism for the detection of non-contact friction.
arXiv Detail & Related papers (2021-03-22T16:25:27Z) - Enhanced decoherence for a neutral particle sliding on a metallic
surface in vacuum [68.8204255655161]
We show that non-contact friction enhances the decoherence of the moving atom.
We suggest that measuring decoherence times through velocity dependence of coherences could indirectly demonstrate the existence of quantum friction.
arXiv Detail & Related papers (2020-11-06T17:34:35Z) - Interfering distinguishable photons [0.0]
It is assumed that distinguishing information in the preparation, evolution or measurement of a system is sufficient to destroy interference.
For more than three independent quantum particles, distinguishability of the prepared states is not a sufficient condition for multiparticle interference to disappear.
arXiv Detail & Related papers (2020-01-22T16:25:12Z)
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.