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Negative-mass exciton polaritons induced by light-matter coupling semiconductor
Dissipation and losses are normally perceived as detrimental to the performance of electronic and photonic devices. Here, the authors demonstrate dissipative coupling between excitons and photons in optical microcavities which they then use to create polaritons with a negative effective mass.
The complex-valued dispersion branches are extracted by fitting the spectrum at each value of k using a two-peak Voigt function, with the peak energy and linewidth corresponding to the real and imaginary parts of the complex eigenvalues of the system Hamiltonian, respectively (see Supplementary Note 5). Note that in samples with the same detuning, \({\Delta }_{0}/(2\sqrt{g{\gamma }_{x}})\) can be made larger than 1 by decreasing dissipative coupling g or narrowing the exciton linewidth γ x, which results in suppressed level attraction and an inversion peak located k= 0 (see Fig. The DBRs used for the microcavities presented in the main text are grown by plasma-enhanced chemical vapour deposition (PECVD) and consist of (bottom) 17.5 and (top) 15.5 alternating quarter-wave stack of SiO x and SiN x, as schematically shown in Fig.
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