  We maintain that the wavefunction is an ensemble property rather than an
individual particle property. For individual particles, we propose an ontology
underwritten by the Heisenberg representation. It consists of properties
represented by deterministic operators, which may have nonlocal dynamics.
Relying on nonlocal dynamics, we show how interference phenomena can be
understood without having to conceive of the quantum state as wave-like.
Nonlocal information is provided by a modular momentum operator. By augmenting
the individual particle ontology with a final state and employing weak
measurements, we show how both interference and which-path can be deduced for
the same system. This situation is most intuitively understood through a
time-symmetric Heisenberg representation. Indeed, we contend that a
time-symmetric operator-based ontology captures the essence of quantum
mechanics, particularly its nonlocal nature, better than any wavefunction-based
ontology.

Quantum Physics