Remote two-time boundary conditions and special states in quantum mechanics

Arno Böhm, Hai Viet Bui, Piotr Kielanowski

Eyal Gruss

We suggest solving the measurement problem by postulating the existence of a special future final boundary condition for the universe. Although this is an extension of the way boundary conditions are usually chosen (in terrestrial laboratories), it is our only deviation from standard quantum mechanics. Using two state vectors, or the "two-state", to describe completely the state of systems of interest, we analyze ideal and "weak" measurements, and show the consistency of our scheme. If the final state of a measuring device is assigned to be one of the possible outcomes of the measurement, an effective reduction is observed after an ideal measurement process. For final conditions chosen with an appropriate distribution, the predictions of standard quantum mechanics may be reconstructed, thus eliminating probability from the description of any single measurement. The interpretation attained, the Teleological Interpretation, is an ontological one; it is local and deterministic. Other special assumptions in the choice of the final boundary condition may explain certain unaccounted for phenomena, or even supply a mechanism for essential free will. In this context we believe that a new conception of time should be adopted.

E. Kapuścik, J. Podlaska, Pawel Szczeszek

Yakir Aharonov, Eyal Gruss

We suggest an interpretation of quantum mechanics, inspired by the ideas of Aharonov et al. of a time-symmetric description of quantum theory. We show that a special final boundary condition for the Universe, may be consistently defined as to determine single classical-like measurement outcomes, thus solving the "measurement problem". No other deviation is made from standard quantum mechanics, and the resulting theory is deterministic (in a two-time sense) and local. Quantum mechanical probabilities are recovered in general, but are eliminated from the description of any single measurement. We call this the Two-time interpretation of quantum mechanics. We analyze ideal measurements, showing how the quantum superposition is, in effect, dynamically reduced to a single classical state via a "two-time decoherence" process. We discuss some philosophical aspects of the suggested interpretation. We also discuss weak measurements using the two-time formalism, and remark that in these measurement situations, special final boundary conditions for the Universe, might explain some unaccounted for phenomena.

Rafael de la Madrid

Friedemann Queißer, Thomas Zell, Rochus Klesse

We investigate the generation of quantum mechanical entanglement of two remote oscillators that are locally coupled to a common bosonic bath. Starting with a Lagrangian formulation of a suitable model, we derive two coupled Quantum Langevin Equations that exactly describe the time evolution of the two local oscillators in presence of the coupling to the bosonic bath. Numerically obtained solutions of the Langevin Equations allow us to study the entanglement generation between the oscillators in terms of the time evolution of the logarithmic negativity. Our results confirm and extend our previously obtained findings, namely that significant entanglement between oscillators embedded in a free bosonic bath can only be achieved if the system are within a microscopic distance. We also consider the case where the bosonic spectral density is substantially modified by imposing boundary conditions on the bath modes. For boundary conditions corresponding to a wave-guide like geometry of the bath we find significantly enlarged entanglement generation. This phenomenon is additionally illustrated within an approximative model that allows for an analytical treatment.