Improved Limits on the Coupling of Ultralight Bosonic Dark Matter to Photons from Optical Atomic Clock Comparisons

We present improved constraints on the coupling of ultralight bosonic dark matter to photons based long-term measurements two optical frequency ratios. In these clock comparisons, we relate ${}^2S_{1/2} (F=0)\leftrightarrow {}^2F_{7/2} (F=3)$ electric-octupole (E3) transition in $^{171}$Yb$^{+}$ that \,{}^2D_{3/2} (F=2)$ electric-quadrupole (E2) same ion, and ${}^1S_0\leftrightarrow\,{}^3P_0$ $^{87}$Sr. Measurements first ratio $\nu_\textrm{E3}/\nu_\textrm{E2}$ are performed via interleaved interrogation both transitions a single ion. The comparison single-ion E3 with strontium lattice yields second $\nu_\textrm{E3}/\nu_\textrm{Sr}$. By constraining oscillations fine-structure constant $\alpha$ measurement results, improve existing bounds scalar $d_e$ for masses range about $ 10^{-24}-10^{-17}\,\textrm{eV}/c^2$. These results constitute an improvement by more than order magnitude over previous investigations most this range. also use repeated limits linear temporal drift its gravity.