Observation of solitons in a quantum degenerate plasma
Event details
| Date | 04.02.2016 |
| Hour | 16:30 › 17:30 |
| Speaker |
Prof. Klaus Muller-Dethlefs The Photon Science Institute and School of Chemistry,University of Manchester, Alan Turing Building, Manchester M13 9PL |
| Location | |
| Category | Conferences - Seminars |
We are reporting a very surprising result:
the observation of solitons in a quantum degenerate plasma.
A very long life-time (>0.3 ms) quantum degenerate molecular Rydberg plasma is produced in the high-density region of a pulsed supersonic jet expansion (10% NO in neon, 5bar) by two-colour resonant excitation of nitric oxide into the high-n Rydberg threshold region close to the ionization limit.
Considering the well-known properties of pulsed supersonic jet expansions the plasma densities reached in our experiments are between 1e13 and 1e16 cm–3 and the electron de Broglie wavelength becomes larger than the Wigner-Seitz radius. Quantum degeneracy implies that the electrons no longer follow the classical Boltzmann distribution but Fermi-Dirac statistics. When a Fermi-fluid is formed, three-body recombination is strongly quenched due to the Pauli-Principle, resulting in extremely long plasma lifetimes.
Subjecting the plasma to high electric field pulses with nanosecond rise- and fall-times induces very sharp resonances in the observed spectrum. These can be interpreted as solitons (= ”standing waves”) of counter-propagating surface plasmons, which are excited by certain combinations of pulsed fields.
The lecture will outline a textbook interpretation for these observations.
the observation of solitons in a quantum degenerate plasma.
A very long life-time (>0.3 ms) quantum degenerate molecular Rydberg plasma is produced in the high-density region of a pulsed supersonic jet expansion (10% NO in neon, 5bar) by two-colour resonant excitation of nitric oxide into the high-n Rydberg threshold region close to the ionization limit.
Considering the well-known properties of pulsed supersonic jet expansions the plasma densities reached in our experiments are between 1e13 and 1e16 cm–3 and the electron de Broglie wavelength becomes larger than the Wigner-Seitz radius. Quantum degeneracy implies that the electrons no longer follow the classical Boltzmann distribution but Fermi-Dirac statistics. When a Fermi-fluid is formed, three-body recombination is strongly quenched due to the Pauli-Principle, resulting in extremely long plasma lifetimes.
Subjecting the plasma to high electric field pulses with nanosecond rise- and fall-times induces very sharp resonances in the observed spectrum. These can be interpreted as solitons (= ”standing waves”) of counter-propagating surface plasmons, which are excited by certain combinations of pulsed fields.
The lecture will outline a textbook interpretation for these observations.
Practical information
- General public
- Free
Organizer
- Prof. Paul Dyson