Accurate Density Response Function of Superfluid He-4 at Freezing Pressure: Is DFT Successful for Superfluid Freezing?

作者：Minoguchi T^*; Galli D E

来源：Journal of Low Temperature Physics, 2011, 162(3-4): 160-166.

DOI：10.1007/s10909-010-0311-3

• Quantum freezing
• Solidification
• DFT
• Density functional theory
• Density response function
• He-4
• Superfluid
• Analytic continuation

An accurate density response function chi(q) of superfluid He-4 at zero temperature and at freezing pressure, up to about q=8 (-1), has been obtained via dynamic structure factors, S(q,omega), extracted from imaginary time density-density correlation functions computed with an exact Path Integral projector method. A new statistical approach (Vitali et al. in Phys. Rev. B 82:174510, 2010) to inverse problems has been used to extract S(q,omega); contrarily to analogous "analytic continuation" approaches, this new method has been found able to separate a well defined elementary excitation peak from multi-phonon contributions. We have applied density functional theory (DFT) to a superfluid-solid transition with the obtained chi(q). With this accurate input, DFT gives unphysically unstable superfluid against solidification which is consistent with conventional works. We discuss the possible defect of DFT.

• 出版日期2011-2