arXiv subjects

Sergio De Filippo

Publications and source records attributed to Sergio De Filippo.

21 records · Page 2Linked to original sources

arXiv2001

Emergence of classicality in non relativistic quantum mechanics through gravitational self-interaction

An explicit dynamical model for non relativistic quantum mechanics with an effective gravitational interaction is proposed, which, as being well defined, allows in principle for the evaluation of every physical quantity. Its non unitary dynamics results from a unitary one in a space with twice as many degrees of freedom as the ordinary ones. It exhibits a threshold for the emergence of classical behavior for bodies of ordinary density on rather long times or instantaneously, respectively at around 10^11 or 10^20 proton masses.

quant-ph↗

arXiv2000

Quantum Computation using Decoherence-Free States of the Physical Operator Algebra

The states of the physical algebra, namely the algebra generated by the operators involved in encoding and processing qubits, are considered instead of those of the whole system-algebra. If the physical algebra commutes with the interaction Hamiltonian, and the system Hamiltonian is the sum of arbitrary terms either commuting with or belonging to the physical algebra, then its states are decoherence free. One of the considered examples shows that, for a uniform collective coupling to the environment, the smallest number of physical qubits encoding a decoherence free logical qubit is reduced from four to three.

quant-ph↗

arXiv2000

Gravitationally induced transition to classical behavior above 10^10 proton masses

The localization length for the center of mass motion of a matter lump, induced by gravitation, is obtained, without using any phenomenological constants. Its dependence from mass and volume is consistent both with unitary evolution of microscopic particles and with the classical behavior of macroscopic bodies required to account for wave function collapse in quantum measurements, the transition between the two regimes being rather sharp. The gravitational interaction of nonrelativistic matter is modelled by a Yukawa Hamiltonian with vanishing pion mass, no gravitational background is needed and the only hypothesis consists in assuming unentanglement between matter and the Yukawa field.

quant-ph↗