Excited electron-bubble states in superfluid 4He: a time-dependent density functional approach

Area of Science:

• Atomic and Molecular Physics
• Quantum Fluids
• Computational Condensed Matter Physics

Background:

• Electron-bubble states in superfluid helium are exotic quantum phenomena.
• Understanding their dynamics requires sophisticated theoretical approaches.
• Previous studies have explored various aspects, but a systematic comparison of computational methods is lacking.

Purpose of the Study:

• To systematically investigate excited electron-bubble states in superfluid helium-4.
• To compare the efficacy of different time-dependent density functional approaches.
• To determine the optimal computational method for studying these states.

Main Methods:

• Employed time-dependent density functional theory (TDDFT).
• Utilized two distinct functionals: a finite-range functional with adiabatic approximation and a zero-range functional with real-time electron evolution.
• Calculated time-resolved absorption spectra and performed long-time real-time evolution of bubble states.

Main Results:

• Detailed comparison of quantitative results from the two TDDFT methods.
• Calculated the time-resolved absorption spectrum for the 1P electron-bubble state.
• Simulated the real-time evolution of the 2P electron-bubble state, observing the breakdown of adiabaticity.

Conclusions:

• The study provides confidence in selecting optimal computational methods for electron-bubble state research.
• Results experimentally verifiable time-resolved absorption spectra can be obtained.
• The physical realization of relaxed, metastable configurations above the 1P state is ruled out.