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Thomas Mieling

Publications and source records attributed to Thomas Mieling.

13 recordsLinked to original sources

Gravitational redshift as a quantum channel: modeling the effects of gravitational redshift in quantum optics

The gravitational frequency shift of light is well understood in the theory of classical electromagnetism. Nevertheless, its description in quantum theory is not yet fully developed. Recent work pointed out inconsistencies in previously developed models aimed at describing the gravitational redshift as an effective multi-mode mixer (MMM) acting on modes of light, but so far a complete solution of these issues was not obtained. Here, we identify the root cause of the MMM model's inconsistency and provide two complementary approaches to correct it: a "natural" one from a field-theoretic perspective, and another adapted to the language of quantum mechanics of finite-dimensional systems. We show that the second approach allows for modeling of the redshift in a multi-mode transmission setup as a quantum channel that can be characterized using standard quantum information-theoretic techniques when restricting the input states to Gaussian states of light.

quant-ph

High-Sensitivity Fiber Interferometer for Gravitational Phase Shift Measurement on Entangled States

In this contribution, we describe the status of our experiment aimed at measuring the gravitationally induced phase shift on path-entangled photons. We use a kilometer-scale fiber interferometer whose arms are vertically displaced in the Earth gravitational potential, allowing photons propagating at different heights to accumulate different phases. To date, this is the first experiment to measure this effect on massless particles, thereby experimentally combining general relativity and quantum mechanics.

quant-ph

Elastically induced phase-shift and birefringence in optical fibers

We compute how elastic deformations of optical fibers affect light propagation therein. Specifically, we consider differences in wave-guiding properties of straight fibers subject to different external temperatures, pressures, and gravitational fields. This is done by solving, perturbatively to first order, the Maxwell equations in deformed and anisotropic fibers using a multiple-scales approximation scheme. We derive explicit expressions for the induced phase shift and birefringence. The phase shift can be expressed in terms of the average radial pressure, longitudinal tension, and change in temperature, while birefringence depends on the quadrupole of the external pressure distribution and the stresses on the axis of the fiber.

physics.optics

Response of an Interferometer Mounted on an Elastic Square Plate to Gravitational Waves

Laser-interferometric gravitational wave detectors are commonly modeled as being at rest in transverse-traceless coordinates (and thus geodesic). In this paper, we analyze what happens if the interferometer is mounted on a material that can undergo elastic oscillations caused by the gravitational wave. We thus compute the response of a two-dimensional elastic material to linearized gravitational radiation and compute the resulting response of a laser interferometer, mounted on such a plate.

gr-qc

Polarization transport in optical fibers beyond Rytov's law

We consider the propagation of light in arbitrarily curved step-index optical fibers. Using a multiple-scales approximation scheme, set-up in Fermi normal coordinates, the full vectorial Maxwell equations are solved in a perturbative manner. At leading order, this provides a rigorous derivation of Rytov's law. At next order, we obtain non-trivial dynamics of the electromagnetic field, characterized by two coupling constants, the phase and the polarization curvature moments, which describe the curvature response of the light's phase and its polarization vector, respectively. The latter can be viewed as an inverse spin Hall effect of light, where the direction of propagation is constrained along the optical fiber and the polarization evolves in a frequency-dependent way.

physics.optics

No Proca Photons

We show that the Proca equation in vacuum, as well as its plausible modifications in dielectric media, is incompatible with experimental evidence, no matter how small the Proca mass is.

physics.class-ph

Relativistic Theory of Elastic Bodies in the Presence of Gravitational Waves

The equations of motion governing small elastic oscillations of materials, induced by gravitational waves, are derived from the general framework of Carter and Quintana. In transverse-traceless gauge, no bulk forces are present, and the gravitational wave is found to act as an effective surface traction. For thin rods, an equivalent description is given, in which there is no surface traction, but a bulk acceleration, which is related to the Riemann curvature of the gravitational wave. The resulting equations are compared to those of the Synge-Bennoun elasticity theory.

gr-qc

Gupta-Bleuler quantization of optical fibers in weak gravitational fields

The theory of gauge-fixed Maxwell equations in linear isotropic dielectrics is developed using a generalisation of the standard $R_\xi$ gauge-fixing term. In static space-times, the theory can be quantised using the Gupta-Bleuler method, which is worked out explicitly for optical fibres either in flat space-time or at a constant gravitational potential. This yields a consistent first-principles description of gravitational fibre-optic interferometry at the single-photon level within the framework of quantum field theory in curved space-times.

quant-ph

The Resolution of Ambiguities in Light Perturbation by Gravitational Waves

Some previously published expressions for the perturbation of light by gravitational waves exhibit pathological behaviour in the limit of parallel propagation. We show that this is caused by similarly pathological initial or boundary data and can thus be remedied by implementing better-behaved initial conditions.

gr-qc

The Electromagnetic Field in Gravitational Wave Interferometers

We analyse the response of laser interferometric gravitational wave detectors using the full Maxwell equations in curved spacetime in the presence of weak gravitational waves. Existence and uniqueness of solutions is ensured by setting up a suitable boundary value problem. This puts on solid ground previous approximate calculations. We find consistency with previous results obtained from eikonal expansions at the level of accuracy accessible to current gravitational wave detectors.

gr-qc

The Response of Laser Interferometric Gravitational Wave Detectors Beyond the Eikonal Equation

The response of Michelson interferometers to weak plane gravitational waves is computed at one order of accuracy beyond the eikonal equation. The modulation of the electromagnetic field amplitude and polarisation are taken into account by solving the transport equations of geometrical optics with boundary conditions adapted to laser interferometry. Considering both DC and balanced homodyne readout schemes, explicit formulae for the interferometer output signals are derived. These signals comprise perturbations of the optical path length, frequency and amplitude, and are shown to be insensitive to polarisation perturbations.

gr-qc

The Response of Optical Fibres to Gravitational Waves

The response of optical fibre modes to plane gravitational waves of low frequency is computed. By solving perturbatively the Maxwell equations for step-index optical fibres in a gravitational wave background and implementing appropriate boundary conditions to describe single-mode fibres, explicit formulae for the perturbations of the phase and the polarisation of the fibre modes are obtained.

gr-qc

On the Influence of Earth's Rotation on Light Propagation in Waveguides

We analyse the influence of Earth's rotation (both around its own axis and around the Sun) on the propagation of light in optical media. This is done using both geometrical optics and a perturbative calculation based on Maxwell's equations in rotating coordinates in flat spacetime. Considering light propagation in cylindrical step-index waveguides in particular, the first order correction to electromagnetic modes is computed. The calculation shows that Earth's rotation causes a weak mode coupling, giving rise to sidebands, whose amplitudes are computed as well. The correction to the dispersion relation derived here allows to assess the anisotropy of light propagation due to Earth's rotation. The linearisation of this result is found to agree numerically with a simple formula derived from geometrical optics.

physics.optics