"Electronic transport through magnetic and Josephson junctions coupled to an
electromagnetic environment"
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The electronic transport trough a tunnel junction (normal, magnetic or
superconducting) is affected by its electromagnetic environment. The hallmark of
such an interaction is the Dynamical Coulomb Blockade (DCB), a quantum
phenomenon associated with the activation of a Coulomb gap at finite voltage due
to inelastic tunneling processes assisted by the environmental degrees of
freedom [1]. On the other hand, the light emitted into the environment is a
direct witness of the electronic transport, offering an alternative way to
access it [2].  In the first part of the talk, I will study the magnetization
dynamics in ferromagnet$\mid$insulator$\mid$ferromagnet and
ferromagnet$\mid$insulator$\mid$normal metal ultra-small tunnel junctions, and
the associated voltage drop in the presence of an electromagnetic environment
assisting the tunneling processes.  We find  that voltages comparable to the
driving frequency $\omega$ can be reached  even for small magnetization
precession cone angles $\theta$, in stark contrast to the case where the
environment is absent [3,4]. We stress some possible applications of such an
effect, such as the detection of  local magnetization precessions in textured
ferromagnets. In the second part, we investigate  the properties of the light
emitted by a voltage-biased Josephson junction coupled to a specific
electromagnetic environment [2,5,6].  We show that depending on the particular
implementations [2,6],  the resulting photons emitted by the junction can show
pronounced non-classical behavior that is quantified by the second-order
photonic correlation function $g^{2}(\tau)$.  We calculate explicitly the
$g^{(2)(\tau)}$ function in different limits, and point out that our theoretical
results are in very good agreement with the recent experimental work in Ref.
[6]. Finally, we discuss some further theoretical and experimental extension of
our work such as the production and detection of photonic squeezed states and
photonic entanglement. 

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[1] G. L. Ingold and Y. Nazarov, Single charge tunneling (Plenum, Berlin
Heidelberg, 1992).
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[2] M. Hofheinz, F. Portier et al, Phys. Rev. Lett, 106, 217005 (2011).
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[3] T. Moriyama, R. Cao, et al, Phys. Rev. Lett., 100, 067602 (2008).
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[4] Mircea Trif and Pascal Simon,
arXiv:1405.5744 (to appear in PRB).
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[5] Mircea Trif and Pascal Simon, (unpublished).
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[6] O. Parlavecchio, F. Portier et al, (to be published).