#!/usr/bin env python3 from formulary import * # Define the functions def psi_squared(x, xi): return np.tanh(x/(np.sqrt(2)*xi))**2 def B_z(x, B0, lam): return B0 * np.exp(-x/lam) def n_s_boundary(): xs = np.linspace(0, 6, 400) xn = np.linspace(-1, 0, 10) B0 = 1.0 fig, ax = plt.subplots(figsize=size_formula_fill_default) ax.axvline(x=0, color='gray', linestyle='--', linewidth=0.8) ax.axhline(y=1, color='gray', linestyle='--', linewidth=0.8) ax.axhline(y=0, color='gray', linestyle='--', linewidth=0.8) ax.fill_between(xn, -2, 2 , color=COLORSCHEME["bg-yellow"], alpha=0.5) ax.fill_between(xs, -2, 2 , color=COLORSCHEME["bg-blue"], alpha=0.5) ax.text(-0.5, 0.9, 'N', color=COLORSCHEME["fg-yellow"], fontsize=14, ha="center", va="center") ax.text(3, 0.9, 'S', color=COLORSCHEME["fg-blue"], fontsize=14, ha="center", va="center") ax.set_xlabel("$x$") ax.set_ylabel(r"$|\Psi|^2$, $B_z(x)/B_\text{ext}$") ax.set_ylim(-0.1, 1.1) ax.set_xlim(-1, 6) ax.grid() lines = [] for i, (xi, lam, color) in enumerate([(0.5, 2, "blue"), (2, 0.5, "red")]): psi = psi_squared(xs, xi) B = B_z(xs, B0, lam) line, = ax.plot(xs, psi, color=color, linestyle="solid", label=f"$\\xi_\\text{{GL}}={xi}$, $\\lambda_\\text{{GL}}={lam}$") lines.append(line) ax.plot(xs, B, color=color, linestyle="dashed") if i == 1: ylam = 1/np.exp(1) ax.plot([0, lam], [ylam, ylam], linestyle="dashed", color=COLORSCHEME["fg2"]) ax.text(lam/2, ylam, r'$\lambda_\text{GL}$', color=color, ha="center", va="bottom") yxi = psi_squared(xi, xi) ax.plot([0, xi], [yxi, yxi], linestyle="dotted", color=COLORSCHEME["fg2"]) ax.text(xi/2, yxi, r'$\xi_\text{GL}$', color=color, ha="center", va="bottom") lines.append(mpl.lines.Line2D([], [], color="black", label=r"$\lvert\Psi\rvert^2$")) lines.append(mpl.lines.Line2D([], [], color="black", linestyle="dashed", label=r"$B_z(x)/B_\text{ext}$")) ax.legend(loc='center right', handles=lines) return fig from mpl_toolkits.mplot3d import Axes3D from scipy.interpolate import griddata def critical_type2(): Jc0 = 100 Bc2_0 = 30 Tc = 90 T = np.linspace(0, Tc, 100) Jc_T = Jc0 * (1 - (T / Tc)**2) Bc2_T = Bc2_0 * (1 - (T / Tc)**2) B = np.linspace(0, Bc2_0, 100) Jc_B = Jc0 * (1 - B / Bc2_0) fig = plt.figure(figsize=size_formula_normal_default) ax = fig.add_subplot(111, projection='3d') ax.plot(T, np.zeros_like(Jc_T), Jc_T, label='$J_c(T)$', color='r') ax.plot(T, Bc2_T, np.zeros_like(Bc2_T), label='$B_{c2}(T)$', color='g') ax.plot(np.zeros_like(Jc_B), B, Jc_B, label='$J_c(B)$', color='b') ax.set_xlim(0, Tc) ax.set_ylim(0, Bc2_0) ax.set_zlim(0, Jc0) # surface # T_grid, B_grid = np.meshgrid(T, B) # Jc_grid = Jc0 * (1 - (T_grid / Tc)**2) * (1 - B_grid / Bc2_0) # surf = ax.plot_surface(T_grid, B_grid, Jc_grid, color='cyan', alpha=0.5) ax.set_xlabel('$T$') ax.set_ylabel('$B_{c2}$') ax.set_zlabel('$J_c$') # ax.legend() ax.grid(True) ax.view_init(elev=30., azim=45) ax.set_box_aspect(None, zoom=0.85) return fig def heat_capacity(): fig, ax = plt.subplots(1, 1, figsize=size_formula_small_quadratic) T_max = 1.7 Cn_max = 3 f_Cn = lambda T: T * Cn_max/T_max Delta_C = f_Cn(1.0) * 1.43 # BCS prediction CsTc = f_Cn(1.0) * (1+1.43) # BCS prediction # exp decay from there f_Cs = lambda T: np.exp(-1 / T + 1) * CsTc Tns = np.linspace(0.0, T_max, 100) Tss = np.linspace(0.0, 1.0, 100) Cns = f_Cn(Tns) Css = f_Cs(Tss) ax.plot(Tns, Cns, label=r"$c_\text{n}$") ax.plot(Tss, Css, label=r"$c_\text{s}$") ax.vlines([1.0], ymin=f_Cn(1.0), ymax=(CsTc), color=COLORSCHEME["fg1"], linestyles="dashed") ax.text(1.05, CsTc - Delta_C/2, "$\\Delta c$", color=COLORSCHEME["fg1"]) ax.set_xlabel(r"$T/T_\text{c}$") ax.set_ylabel(r"$c$ [a.u.]") ax.legend() return fig if __name__ == "__main__": export(n_s_boundary(), "cm_super_n_s_boundary") export(critical_type2(), "cm_super_critical_type2") export(heat_capacity(), "cm_super_heat_capacity")