Information transfer during the universal gravitational decoherence

Abstract

Recently Pikovski et al. (Nat Phys 11:668, 2015) have proposed in an intriguing universal decoherence mechanism, suggesting that gravitation may play a conceptually important role in the quantum-to-classical transition, albeit vanishingly small in everyday situations. Here we analyze information transfer induced by this mechanism. We show that generically on short time-scales, gravitational decoherence leads to a redundant information encoding, which results in a form of objectivization of the center-of-mass position in the gravitational field. We derive the relevant time-scales of this process, given in terms of energy dispersion and quantum Fisher information. As an example we study thermal coherent states and show certain robustness of the effect with the temperature. Finally, we draw an analogy between our objectivization mechanism and the fundamental problem of point individuation in General Relativity as emphasized by the Einstein's Hole argument.

Gravitational mass of composite systems

“…Many different experiments have confirmed this principle [3][4][5][6][7][8][9][10], with the most stringent bound on its violations currently being a few parts in 10 −14 [9]. Recently, it was shown that the quantized gravitational interaction with composite systems yields novel effects and experiments [11][12][13][14][15][16][17][18][19][20][21][22][23][24], which rely on the coupling of gravity to the total energy of composite systems, as dictated by the equivalence principle.…”

Entanglement and objectivity in pure dephasing models

“…The measurement Hamiltonian which is used to study the emergence of spectrum broadcast structure states is, in fact a special case of the general Hamiltonian which leads to pure dephasing evolutions [6][7][8][9][10][11][12][13] in a systemenvironment scenario [30,31]. The Hamiltonian is given byĤ…”

“…To study situations when the emergence of objectivity is possible in the above sense of SBS creation, typically system-environment interactions are taken into account which lead to pure dephasing of the qubit [6][7][8][9][10][11][12][13] after the environmental degrees of freedom are traced out. These types of interactions describe situations when the T * 2 times are much shorter than the T 1 times (the decay of phase coherence is much faster than relaxation) are fairly common in solid state scenarios.…”

System information propagation for composite structures

“…II C, we investigate the asymptotic behaviour of the orthogonalization and decoherence processes in spin models using the Weak Law of Large Numbers (LLN). We develop some tools which are useful for the analysis of the quasi-periodic functions often occurring in similar models [1,3,5,30,31]. In sec.…”