We study an analytical model of a Rashba nanowire that is partially covered by and coupled to thin superconducting layer, where the uncovered region forms quantum dot. find that, even if there no topological phase possible, trivial Andreev bound state becomes pinned exponentially close zero energy as function magnetic field strength when length dot tuned with respect its spin-orbit such resonance condition Fabry-Perot type satisfied. In this case, we remains near for Zeeman energies exceed...

We discuss the problem of gauge fixing for strongly correlated electrons coupled to quantum light, described by projected low-energy models such as those obtained within tight-binding methods. Drawing from recent results in field optics, we present a general approach write down light-matter Hamiltonian either dipole or Coulomb which is explicitly connected unitary transformation, thus ensuring equivalence even after projection. The features linear coupling and an instantaneous...

Abstract Controlling the topological properties of quantum matter is a major goal condensed physics. A effort in this direction has been devoted to using classical light form Floquet drives manipulate and induce states with non-trivial topology. different route can be achieved cavity photons. Here we consider prototypical model for phase transition, one-dimensional Su-Schrieffer-Heeger model, coupled single mode cavity. We show that affect system, including finite-length energy spectrum...

We study one-dimensional $p$-wave superconductors capacitively coupled to a microwave stripline cavity. By probing the light exiting from cavity, one can reveal electronic susceptibility of superconductor. analyze two superconducting systems: prototypical Kitaev chain, and topological semiconducting wire. For both systems, we show that photonic measurements, via susceptibility, allows us determine phase transition point, emergence Majorana fermions, parity their ground state. all these...

We theoretically study a Josephson junction based on semiconducting nanowire subject to time-dependent flux bias. establish general density-matrix approach for the dynamical response of Majorana and calculate resulting flux-dependent susceptibility using both microscopic effective low-energy descriptions nanowire. find that diagonal component susceptibility, associated with dynamics state populations, dominates over standard Kubo contribution wide range experimentally relevant parameters....

We study both analytically and numerically the role of orbital effects caused by a magnetic field applied along axis semiconducting Rashba nanowire in topological regime hosting Majorana fermions. demonstrate that can be effectively taken into account one-dimensional model shifting chemical potential, and, thus modifying criterion. focus on energy splitting between two fermions finite find striking interplay Zeeman this splitting. In limit strong spin-orbit interaction, we regimes where...

We consider a one-dimensional topological superconductor hosting Majorana bound states at its ends coupled to single mode cavity. In the strong light-matter coupling regime, electronic and photonic degrees of freedom hybridize resulting in formation polaritons. find polariton spectrum by calculating cavity photon spectral function electron-photon system. phase, lower energy modes are formed bulk-Majorana transitions photons also sensitive parity. trivial emerge due bulk-bulk across gap...

We study the topological phase diagram of a setup composed two nanowires with strong Rashba spin-orbit interaction subjected to an external magnetic field and brought into proximity bulk $s$-wave superconductor in presence supercurrent flowing through it. The reduces critical values Zeeman energy crossed Andreev superconducting pairing required reach characterized by one Majorana bound state localized at each system end. demonstrate that, even regime being smaller than direct pairing,...

We study a topological superconducting nanowire that hosts gliding Majorana zero modes in the presence of microwave cavity field. show decay rate depends on both parity encoded by and their motion, absence any direct overlap wavefunctions. That is because extended bulk states with states, facilitate momentum-resolved spectroscopy, acting as to modify interference pattern via momentum boost. Moreover, we demonstrate these non-local effects are robust against moderate disorder chemical...

We theoretically study a one-dimensional $p$-wave superconducting mesoscopic ring interrupted by weak link and coupled inductively to microwave cavity. establish an input-output description for the cavity field in presence of ring, identify electronic contributions response their dependence on various parameters, such as magnetic flux, chemical potential, frequency. show that is $4\ensuremath{\pi}$ periodic function flux topological region, stemming from so-called fractional Josephson...

We consider a superconducting microwave cavity capacitively coupled to both quantum conductor and its electronic reservoirs. analyze in detail how the measurements of field, which are related charge susceptibility, can be used extract information on transport properties conductor. show that asymmetry capacitive couplings between reservoirs plays crucial role relating optical properties. For asymmetric couplings, photonic probe finite low-frequency admittance conductor, real part is...

We consider a two-dimensional electron gas with Rashba spin-orbit interaction (SOI) partially covered by an s-wave superconductor, where the uncovered region remains normal but is exposed to effective Zeeman field applied perpendicular plane. find analytically and numerically Andreev bound states (ABSs) formed in show that, due SOI tuning parameters of system deeply into topologically trivial phase, one can reach regime energy lowest ABS becomes pinned close zero as function field. The such...

We study analytically and numerically the renormalization of $g$-factor in semiconducting Rashba nanowires (NWs), consisting a normal superconducting section. If potential barrier between sections is high, quantum dot (QD) formed For harmonic (hard-wall) confinement, effective all QD levels suppressed exponentially (power law) product spin-orbit interaction (SOI) wave vector length. two removed, emerging Andreev bound states less strongly. In strong SOI regime, if chemical tuned to energy...

Poor man's Majorana Bound States (MBS) arise in minimal Kitaev chains when the parameters are fine-tuned to a sweet spot. We consider an interacting two-site chain coupled single-mode cavity and show that spot condition can be controlled with frequency hopping between sites. Furthermore, we demonstrate photon-mediated effective interactions used screen intrinsic interactions, improving original quality of MBS. describe experimental signatures transmission detect their presence quality. Our...

We present a comprehensive theoretical study of interacting and disordered topological phases coupled Kitaev wires, which may support further realistic applications Majorana fermions. develop variety analytical, mathematical numerical methods for one two-coupled associated with marker accessible from real-space correlation functions on the wire(s). verify stability superconducting phase quantify disorder effects close to quantum transitions, e.g. through two-point or using renormalization...

We discuss the theory of linear and nonlinear spectroscopy an rf superconducting quantum interference device (rf-SQUID) coupled to a Josephson spectrometer. Recent experimental measurements on this system have shown strongly absorption line shape, whose current peak maximum undergoes forward-backward bending transition depending value rf-SQUID phase. show that can be qualitatively understood by mapping dynamics driven onto generalized Duffing oscillator, with tunable drive nonlinearity,...

We consider a one-dimensional topological superconductor hosting Majorana bound states at its ends coupled to single mode cavity. In the strong light-matter coupling regime, electronic and photonic degrees of freedom hybridize resulting in formation polaritons. find polariton spectrum by calculating cavity photon spectral function electron-photon system. phase lower energy modes are formed bulk-Majorana transitions photons also sensitive parity. trivial emerge due bulk-bulk across gap...