  The persistent debate about the reality of a quantum state has recently come
under limelight because of its importance to quantum information and the
quantum computing community. Almost all of the deliberations are taking place
using the elegant and powerful but abstract Hilbert space formalism of quantum
mechanics developed with seminal contributions from John von Neumann. Since it
is rather difficult to get a direct perception of the events in an abstract
vector space, it is hard to trace the progress of a phenomenon. Among the
multitude of recent attempts to show the reality of the quantum state in
Hilbert space, the Pusey-Barrett-Rudolph theory gets most recognition for their
proof. But some of its assumptions have been criticized, which are still not
considered to be entirely loophole free. A straightforward proof of the reality
of the wave packet function of a single particle has been presented earlier
based on the currently recognized fundamental reality of the universal quantum
fields. Quantum states like the atomic energy levels comprising the wave
packets have been shown to be just as real. Here we show that an unambiguous
proof of reality of the quantum states gleaned from the reality of quantum
fields can also provide an explicit substantiation of the reality of quantum
states in Hilbert space.
