Tag: Anharmonicity
Noise-canceling method computes finite-temperature elastic constants
What the study found The study shows that elastic constants, which are central material properties, can be computed at finite temperature in both thermally ordered and disordered systems using a noise-cancellation approach. Why the authors say this matters The authors say this matters because finite-temperature calculations often have poor signal-to-noise ratios, strong anharmonic effects, or…
Ultrafast spectroscopy directly measures Raman phonon anharmonicity
What the study found The study reports that ultrafast double pump-probe spectroscopy can directly observe frequency shifts of Raman phonons, which are lattice vibrations that can be detected by light, as a function of oscillation amplitude. It also reports that this approach can separate coherent effects from quasi-harmonic sources such as temperature and changes in…
Conic optimization tightened thermal bootstrap bounds in large-N matrix models
What the study found The study found that thermal bootstrap bounds for large-N matrix quantum mechanics can be improved without logarithmic relaxation by using a Quantum Information Conic Solver. In the one-matrix case, the stricter bounds gave a value for the first long string excited energy that is within 0.001% of the physical value. Why…