14.09.2014 Views

pdf, 9 MiB - Infoscience - EPFL

pdf, 9 MiB - Infoscience - EPFL

pdf, 9 MiB - Infoscience - EPFL

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

3.4. RESULTS AND DISCUSSION 77<br />

0<br />

0<br />

-0.2<br />

-0.4<br />

e pot<br />

e kinetic<br />

-0.4<br />

-0.8<br />

0 0.4 0.8<br />

Hole doping δ<br />

0 0.4 0.8<br />

Hole doping δ<br />

Figure 3.17: Kinetic (e kinetic ) and exchange energy (e pot ) per site for the<br />

Gutzwiller (bold line), the commensurate flux phase with 2π/3 flux per plaquette<br />

(open circles), with π/2 flux per plaquette (dashed line), the d + /AF/J<br />

wavefunctions (filled squares), and the polarized wavefunctions (lines) with<br />

S z =11, 18, 21, 24, 28. The polarized wavefunction are shown from top to bottom<br />

with increasing (decreasing) polarizations in the left (right) figure. the left figure<br />

and decreasing polarization.<br />

tivity and the spin-density wave was found: the energy is minimized either for<br />

(∆ k =0,f(Q) ≠0),or(∆ k ≠0,f(Q) = 0) depending on the doping, with ∆ k of<br />

d x 2 −y 2 + id xy symmetry type in the latter case. Measuring the on-site magnetization<br />

value, we found that the spin-density wave forms a collinear stripe-like<br />

pattern in the spin degrees of freedom, whereas the charge is found to be uniformly<br />

distributed among the lattice sites, as expected (see Fig. 3.16). The amplitude<br />

of the on-site magnetization is shown in Fig. 3.15 as a function of doping.<br />

3.4.4 Phase diagram of the model<br />

Based on our wavefunction we can now give the phase diagram for the doped<br />

system on the triangular lattice. The phase diagram, summarizing the various

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!