**A Brief Summary of the Significant Scientific Contributions**

Dipankar Home is one of the early Indian researchers to have initiated investigations on *Foundational issues* of *Quantum Mechanics*
since 1980s and was the first Indian researcher to have done his Ph. D. work on this topic. This line of study has gradually evolved
to become amenable to a variety of fundamentally important experiments, as well as has become intimately related to the currently one
of the frontier areas of science, viz. *Quantum Information Theory* and its applications in *Quantum Communication, Quantum Cryptography
and Quantum Computation.*

Among his **137** Research Publications with his various collaborators that have been cited in **20 Books**, and that have Total Citation Number around **1967** (Google Scholar),
Home’s notable contribution has been Two distinctive Research-level Books: **“Conceptual Foundations of Quantum Physics – An Overview from Modern
Perspectives”** (Plenum, 1997), with a Foreword by Nobel laureate **Anthony Leggett**, and (ii)** ***“Einstein’s Struggles with Quantum Theory: A Reappraisal”* (Springer, 2007),
co-authored with Andrew Whitaker, having a *Foreword* by **Roger Penrose**. Both these books have been peer-appreciated in *Physics Today*
(October, 1998 and May, 2008 respectively), apart from the former being also appreciatively reviewed in *The Times* (London), *Higher Education
Supplement* (25 September, 1998), *Foundations of Physics*, Vol. 31, pp. 855 -857 (2001), and in *Progress in Quantum Electronics*,
Vol. 22, pp. 41-42 (1998) by some of the leading experts in the area of Quantum Foundations. These two books have Total Citation Number around **229** (Google Scholar).

Among the manifold research works of Home with his collaborators, the most significant ones are briefly mentioned as follows:

**A)** At the core of the various intriguing questions raised by Einstein,
Schrödinger and others about foundational aspects of Quantum Mechanics (QM) is the QM incompatibility with the everyday
notion of *Macrorealism* (MR) which assumes that, at any instant, a system is in a definite state having definite properties,
irrespective of any measurement. The latest work by Home and his collaborators [**Physical Review Letters** 120, 210402 (2018)]
opens up a novel direction for extending the tests of MR as well as of the *nonclassicality* of QM for massive systems much
beyond those possible by other methods.

In particular, using the Leggett-Garg inequality, the work by Home and his
collaborators shows that the QM violation of MR for large mass systems is testable for a system like harmonic oscillator
which has a well defined classical description and is initially in a state which is the most classical-like of all quantum
states, viz. the harmonic oscillator coherent state. Testing of this scheme using the setup proposed in this work for
optically trapped and oscillating nano-scale objects of mass about million to billion times heavier than hydrogen atoms is
being implemented by Hendrik Ulbricht and his group at University of Southampton, UK.

**B)** A hitherto unexplored connection was revealed between two profound
features of QM, viz. *Quantum Indistinguishability* (QI) and *Quantum Entanglement* (QE) by invoking QI for formulating an
arbitrarily efficient generic scheme that can entangle, using any spin-like variable, any two identical bosons/fermions
coming from independent sources [**Physical Review Letters** 88, 050401 (2002)].

Such an efficient generic scheme for generating QE is of considerable importance since QE lies at the core of Quantum
Foundations and various applications of Quantum Information Theory. Furthermore, this work suggested a novel form of
complementarity between particle distinguishability and the amount of entanglement generated, besides providing one of the
ingredients of the seminal work by C. W. J. Beenakker et al. [**Physical Review Letters** 93, 020501 (2004)] which initiated
studies on Free-Electron Quantum Computation.

**C)** The above-mentioned line of study blending QI and QE was enriched by
uncovering an earlier unnoticed property of QE involving any two identical particles which has been called ‘*Duality in
Entanglement*’ [**Physical Review Letters** 110, 140404 (2013)]. Importantly, this property enables studying the transition from
QI to Classical Distinguishability, as well as can be an effective tool for empirically probing aspects of QI for
mesoscopic/macroscopic molecules without requiring to bring them together, thereby avoiding the effect of interaction
between them.

For photons, this predicted property of ‘*Entanglement Duality*’ (involving the manifestation of polarization entanglement
when the photons are labelled by different momenta, or, for the same source, manifesting momentum entanglement when the
photons are labelled by polarization variables) has been *experimentally verified* at Tsinghua University, Beijing [New Journal
of Physics 16, 083011 (2014)], followed by another *experimental study* at INRIM, Torino [**Physical Review A** 91, 062117 (2015)]
using Bell measurements in order to probe a few subtle aspects of our predicted ‘Entanglement Duality’.

**D)** One of the earliest ideas for testing the fundamental property of
*Quantum Contextuality* was formulated by introducing the notion of path-spin *intraparticle entanglement* as applied to a
Bell-type inequality involving the path and spin variables pertaining to a single spin-1/2 particle
[**Physics Letters A** 279, 281 (2001)].

This was *experimentally verified* by the Neutron Interferometric group at Atominstitut, Vienna [**Nature** 425, 45 (2003)].

**E)** A novel manifestation of *wave-particle duality* of *single photon states*
providing fresh insights into the Bohrian principle of wave particle complementarity was formulated by invoking the quantum
mechanical treatment of *tunneling* of single photon states in the context of a double-prism device
[*Physics Letters A* 153, 403 (1991); 168, 95 (1992)].

This proposal was *experimentally realized* at the Hamamatsu Photonics Central Research Laboratory, Japan
[**Physics Letters A** 68, 1 (1992)].

**F)** A striking *biomolecular* example was formulated in order to empirically
probe aspects of the *Quantum Measurement Problem* in the *mesoscopic domain* [**Physical Review Letters** 76, 2836 (1996)] by using
the biochemical property of photolyase enzyme attachment to *uv-absorbed* DNA molecules serving as detectors of *uv photons*.
This work was one of the earliest of its kind, using the biomolecular phenomenon in order to provide empirically relevant
constraints on the various approaches seeking to address the much debated Quantum Measurement Problem.

**G)** A series of investigations concerning an intriguing Quantum Mechanical
effect known as the *Quantum Zeno Effect* (inhibition of the time evolution of a system due to repeated projective measurements)
throwing light on the various critical aspects of its treatment, its deep-seated conceptual implications and clarifying the
question of its experimental realizability, culminated in a comprehensive and widely cited in-depth analysis
[**Annals of Physics** 258, 237 (1997)] of this effect which is now well recognized as one of the key fundamental quantum
features.

**H)** Wigner’s argument seeking to demonstrate *Quantum Nonlocality* that was
originally formulated only for bipartite states has been successfully generalized for an *arbitrary multipartite* state,
thereby providing a powerful method for obtaining *multipartite Bell-type inequalities* in order to probe Quantum Nonlocality
pertaining to the states of multipartite systems [**Physical Review A** 91, 012102 (2015)]. The efficacy of such obtained
multipartite Bell-type inequalities has been demonstrated for the *quadripartite entangled states*, thus opening up a novel
direction in this area of study concerning multipartite Quantum Nonlocality which is of much contemporary interest.

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