  Higher superconducting critical temperature and large-area epsilon-near-zero
interfaces are two long-standing goals of Condensed Matter Physics and Optics.
Motivated by the recent advancements of experimental interests on metallic
nanostructures, we have theoretically investigated some selected bimetallic FCC
combinations starting from large-area interface to embedded and doped
two-dimensional (2D) nanostructures. Using different first-principles
techniques, encompassing density functional theory (DFT), time-dependent DFT
(TDDFT), phonon and DFT-coupled quantum transport, we propose the prospects of
some selective bimetallic nanostructures like Au/Ag and Pt/Pd to exhibit exotic
electronic phenomena. For 2D doped and embedded nanostructures of these
systems, non-trivial band-structure and Fermi-surface topology may be
emblematic to the presence of instabilities like charge density waves. We
specifically highlight the optical attributes extracted from the TDDFT
calculations for these systems, where interfacial morphology induced
band-localization leads to near-zero behavior of both real and imaginary parts
of the dynamical dielectric response is observed in the ultra-violet to visible
(UV-vis) optical range. Low-energy intra-band plasmonic oscillations present
for individual metallic surfaces are completely suppressed for embedded and
doped nanostructures. Phonon-dispersion of the model systems indicates the
presence of soft phonons and dynamical instabilities. Quantum transport
calculations on simplest possible device made out of these bimetallic systems
reveals generation of highly transmitting pockets over the cross-sectional area
for some selected device geometry. We envisage that, if observed
experimentally, such systems may lead to many fascinating physics and
applications in many diverse fields ranging from condensed matter physics to
optics or even more.
