Related Experiment Video
Updated: Dec 25, 2025
10:00
Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
13.1K
Long-Lived Nuclear Coherences inside Helium Nanodroplets
Bernhard Thaler1, Miriam Meyer1, Pascal Heim1
1Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria.
Physical Review Letters
|April 4, 2020
Summary
Superfluid helium nanodroplets enable femtosecond time-resolved spectroscopy of single molecules. This quantum solvent allows detailed study of molecular dynamics and coherence in a unique, low-perturbation environment.
Area of Science:
- Physical Chemistry
- Spectroscopy
- Quantum Systems
Background:
- Femtosecond time-resolved spectroscopy is crucial for understanding molecular dynamics.
- Studying weakly bound or reactive systems has been challenging due to solvent interactions.
- Superfluid helium nanodroplets offer a unique, ultra-cold environment for molecular studies.
Purpose of the Study:
- To demonstrate the suitability of superfluid helium nanodroplets for time-resolved spectroscopic studies of single molecules.
- To investigate molecular dynamics in a low-perturbation quantum solvent.
- To explore the influence of microsolvation on intramolecular dynamics.
Main Methods:
- Utilizing femtosecond time-resolved spectroscopy.
- Employing superfluid helium nanodroplets as a cryogenic solvent (0.4 K).
- Observing vibrational wave packet motion of indium dimers (In2).
Main Results:
- Superfluid helium nanodroplets enable time-resolved studies of single molecules.
- The perturbation from helium nanodroplets is 10-100 times lower than conventional solvents.
- Long nuclear coherence in a dissipative environment can be studied.
Conclusions:
- Superfluid helium nanodroplets are a powerful tool for studying molecular dynamics with high nuclear coherence.
- This technique opens new avenues for investigating solvent effects on intramolecular dynamics across a wide coupling range.
Related Concept Videos
02:13Nuclear Binding Energy
14.5K
The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect indicates a “loss” in mass of 4.0331 amu – 4.0026 amu = 0.0305 amu. The loss in mass accompanying the formation of an atom from protons, neutrons, and electrons is due to the conversion of that mass into energy that is evolved as the atom forms. The nuclear binding energy is the energy produced when the atoms’ nucleons are bound...
14.5K
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.2K
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
1.2K
01:28Atomic Nuclei: Types of Nuclear Relaxation
822
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
822
02:45Nuclear Fusion
33.5K
The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process called fusion. The principal source of energy in the sun is a net fusion reaction in which four hydrogen nuclei fuse and ultimately produce one helium nucleus and two positrons.
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
33.5K
03:18Nuclear Stability
22.5K
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together...
To hold positively charged protons together...
22.5K
01:04¹³C NMR: ¹H–¹³C Decoupling
1.6K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.6K