Shubnikov-de Haas quantum oscillations reveal a reconstructed Fermi surface near optimal doping in a thin film of the cuprate superconductor ${\mathrm{Pr}}_{1.86}{\mathrm{Ce}}_{0.14}{\mathrm{CuO}}_{4\pm \delta }$

We study magnetotransport properties of the electron-doped superconductor ${\mathrm{Pr}}_{2-x}{\mathrm{Ce}}_x{\mathrm{CuO}}_{4\pm \delta }$ with $x=0.14$ in magnetic fields up to 92 T, and observe Shubnikov-de Haas magnetic quantum oscillations. The oscillations display a single frequency $F=255\pm 10$ T, indicating a small Fermi pocket that is $\sim 1\%$ of the two-dimensional Brillouin zone and consistent with a Fermi surface reconstructed from the large holelike cylinder predicted for these layered materials. Despite the low nominal doping, all electronic properties including the effective mass and Hall effect are consistent with overdoped compounds. Our study demonstrates that the exceptional chemical control afforded by high quality thin films will enable Fermi surface studies deep into the overdoped cuprate phase diagram.

Figure 1

Low-temperature magnetoresistance of a superconducting ${\mathrm{Pr}}_{2-x}{\mathrm{Ce}}_x{\mathrm{CuO}}_{4\pm \delta }$ thin film (pictured) measured to 92 T at temperatures between 2 and 30 K. Inset (right scale): Sample magnetoresistance with a smooth background subtracted, showing magnetic oscillations that are suppressed with increasing temperature.

Figure 2

Resistivity and magnetotransport in a $x=0.14 {\mathrm{Pr}}_{2-x}{\mathrm{Ce}}_x{\mathrm{CuO}}_{4\pm \delta }$ thin film. (a) $\rho -T$ curve; the sample shows a superconducting transition at $T_c=22\mathrm{K}$ and a residual resistivity ratio $\equiv \rho \left(300\text{K}\right)/\rho \left(30\text{K}\right)=10.2$. (b) Hall coefficient $R_H={\rho }_{yx}/B$ as a function of temperature. (c) Hall (${\mu }_H$), magnetoresistance (${\mu }_{\mathrm{MR}}$), and Dingle (${\mu }_D$) mobilities calculated as described in the text. (d) $\rho \left(B\right)$ magnetoresistance traces measured in dc fields at temperatures between 1.8 and 30 K.

Figure 3

(a) After subtracting a polynomial background, magnetic quantum oscillations periodic in inverse field are visible below 0.02 ${\mathrm{T}}^{-1}$, with period 1/255 ${\mathrm{T}}^{-1}$. (Curves have been vertically offset for clarity.) (b) Location of maxima (up triangles) and minima (down triangles) of the QO traces versus inverse field. (c) FFTs of the QO data, showing a single peak near 250 T.

Figure 4

Decay of the quantum oscillation amplitude as a function of temperature, evaluated both using the FFT amplitude (circles) and resistance at fixed fields $\mathrm{\Delta }R\left(T\right)$ (triangles); together they indicate a quasiparticle effective mass $m^{*}=0.43\pm 0.05m_e$ (continuous and dashed lines).

Figure 5

Schematic holelike PCCO Fermi surface according to band theory for $x=0.14$ (left), reconstruction picture at and below optimal doping (center), and the 2D FS areas (right) shown by magnetic quantum oscillation ($A_F$) and estimated using Hall effect measurements ($A_{\mathrm{Hall}}$) as discussed in the text.