Figure 1

Solid line: Fermi surface of electron doped cuprates at $x=0.17$ calculated from Eq. (1) using the standard band parameters given in the text and overlaid on a false-color representation of the near-chemical-potential photoemission intensity (Ref. 26) derived from angle-resolved photoemission measurements of an NCCO sample with nominal electron doping $x=0.15$. In this measurement, the Fermi surface is located in the light-shaded region.Reuse & Permissions

Figure 2

Observed quasiparticle dispersions (heavy solid lines) from angle-resolved photemission measurements on ${\mathrm{Nd}}_{1.85}{\mathrm{Ce}}_{0.15}\mathrm{Cu}{\mathrm{O}}_4$ (Ref. 26) compared to the tight-binding model prediction (dashed lines) and to the tight-binding model with hopping parameters reduced by a factor of 2 (light solid line). Panel (a): zone diagonal $[(0,0)\to (\pi ,\pi )]$; Panel (b): zone face $[(\pi ,0)\to (\pi ,\pi )]$.Reuse & Permissions

Figure 3

Scattering rates (upper panel) and mass enhancements (lower panel) derived from room-temperature optical data for $x=0.17$ material, compared to results of fits and to corresponding single-particle rates. Light dotted lines: optically defined scattering rate ${\Gamma }_{\mathrm{opt}}$ and mass enhancement $m^{*}∕m_{\mathrm{opt}}$ obtained from optical data using Eq. (9). Solid lines: ${\Gamma }_{\mathrm{opt}}$ and $m^{*}∕m_{\mathrm{opt}}$ obtained by applying Eq. (9) to theoretical fit to optical conductivity. Heavy dashed lines: “single-particle” mass and (the negative of twice the) scattering rate obtained from model self-energy used in fits to $x=0.17$ room-temperature conductivity.Reuse & Permissions

Figure 4

Measured-room temperature conductivities of electron-doped cuprates at near-optimal doping.Reuse & Permissions

Figure 5

(Color online) Main panels: real (dashed line) and imaginary (dotted line) parts of room-temperature measured conductivity of $x=0.17$ PCCO film (upper panel) and crystal (lower panel), compared to theoretical model (solid and dash-dot lines). Inset: measured conductivity over the wider frequency range $0–2\mathrm{eV}$.Reuse & Permissions

Figure 6

(Color online) Kinetic energy for electron- and hole-doped cuprates, obtained by integrating measured room-temperature conductivities up to cutoff frequencies ${\Omega }_c=0.2\mathrm{eV}$ and ${\Omega }_c=0.8\mathrm{eV}$ and normalizing to the (doping-dependent; see Table ) band theory value, plotted against doping. The PCCO film data (squares) from Ref. 17 PCCO crystal data (stars) from Ref. 18, NCCO data (triangles) from Ref. 16, ${\mathrm{La}}_{2-x}{\mathrm{Sr}}_x\mathrm{Cu}{\mathrm{O}}_4$ data (plus) from Refs. 36, 37. Note that the doping for the PCCO crystal has been shifted from the nominal $x=0.15$ to the value $x=0.17$ inferred from the observed superconducting transition temperatureReuse & Permissions

Figure 7

Upper panel: Frequency dependence of difference in room-temperature kinetic energy between $x=0.11$ sample and $x=0.17$ (solid line), $x=0.15$ (dashed line), and $x=0.13$ (dotted line). Lower panel: Frequency dependence of difference of $T=25\mathrm{K}$ and $T=300\mathrm{K}$ kinetic energy of $x=0.17$ sample.Reuse & Permissions

Figure 8

Comparison of optical mass and scattering rate obtained from PCCO films and single crystal.Reuse & Permissions

Figure 9

Real part of the measured room-temperature conductivity (dashed lines) compared to theoretical model (solid lines) for $x=0.11$, 0.13, and 0.15.Reuse & Permissions

Figure 10

Frequency-dependent single-particle mass enhancement $m^{*}∕m=1-\mathrm{Re}\Sigma \left(\omega \right)∕\omega$ inferred from self-energy only analysis of room-temperature conductivity.Reuse & Permissions

Figure 11

Main panels: measured dissipative (upper) conductivity and reactive (lower) conductivities (dashed lines) compared to model calculation (solid lines) for $x=0.17$ and $T=25\mathrm{K}$. Inset: expanded view of the low-frequency regime.Reuse & Permissions

Figure 12

The $T=25\mathrm{K}$ scattering rate (upper panel) and mass enhancement (lower panel) derived from optical data (light dashed line), from theoretical fits to optical data for the $x=0.17$ sample (light solid line) compared to “single-particle” mass and scattering rate obtained from model self-energy (heavy dashed lines).Reuse & Permissions

Figure 13

Measured conductivity for $x=0.13$ sample at room temperature (dashed line) and low temperature (dotted line). A shift in spectral weight, characteristic of the opening of a density wave gap, is evident.Reuse & Permissions

Figure 14

Energy dispersion curves (electron spectral function as function of energy for fixed momentum) calculated for $300\mathrm{K}$ best-fit optical parameters and shifted for clarity. Top panel: momenta along zone face $p=\mathbf{(}\pi ,(0,0.1,0.2,0.3,0.4)*\pi \mathbf{)}$ highest curve, π, 0.4 π. Lower panel: zone diagonal, $p=0.2,0.3,0.4,0.45*(\pi ,\pi )$ (highest curve, 0.45 π, 0.45 π).Reuse & Permissions