Interaction Between Macroscopic Quantum Systems and Gravity

Abstract

We review experiments and theoretical models about the possible mutual interplay between the gravitational field and materials in the superconducting state or other macroscopic quantum states. More generally, we focus on the possibility for quantum macrosystems in a coherent state to produce local alterations of the gravitational field in which they are immersed. This fully interdisciplinary research field has witnessed a conspicuous progress in the last decades, with hundreds of published papers, and yet several questions are still completely open.

Superconductor Meissner Effects for Gravito-Electromagnetic Fields in Harmonic Coordinates Due to Non-Relativistic Gravitational Sources

“…similar to what is shown in [14,15,30,35,40,42,44,47]. However, this is not how the presence of gravity appears in Eq.…”

“…31 can be dropped and still maintain consistency. However, it is also shown in Supplementary Appendix SB that an expansion to second order in the perturbation, and fourth order in the momentum, introduces seven more terms that 6 The coupling term involving the tensor part of the perturbation, h ij P i P j /(2m), is also found in [14,16,30,[33][34][35]. In [16,34], an interaction Lagrangian density, L int 1 2 h μ] T μ] , leads to an interaction Hamiltonian density, H int 1 2 h μ] T μ] , with an associated interaction Hamiltonian for a particle given as H int h ij P i P j /(2m).…”

“…16. In fact, errors in the Hamiltonian and the coupling rule are related since starting with a Hamiltonian of the form H 1 2m P 2 + V, and assuming P → P − e A − m h, leads directly to the result H 1 2m ( P − e A − m h) 2 + V. This Hamiltonian appears in a multitude of papers, someof which are [14,15,19,25,26,30,32,35], [40][41][42][43][44][45][46][47][48][49][50].…”

“…Over the course of many decades, researchers have investigated a wide variety of new theoretical gravitational effects and the possibility of experiments that can detect these effects. Many of these include the use of superconductors [1][2][3], [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], [30][31][32][33][34][35], [38][39][40][41][42][43][44][45][46][47], [49,50,58,59,62], [63][64][65][66], [71][72][73][74][75]…”

A tale of analogies: a review on gravitomagnetic effects, rotating sources, observers and all that

“…Other experimental proposals refer to the gravitational properties of coherent quantum systems, such as superconductors or superfluids; more generally speaking, also the quantum features of gravitation could be relevant [132][133][134] (see also section 8 below). Some recent reviews by Gallerati et al [135], Gallerati and Ummarino [136] carefully analyse these topics. For instance, rotating superconductors [137][138][139] showed apparently singular properties and it was suggested that they can be explained by gravitomagnetic fields much larger than those predicted by GR [140,141].…”