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Published on: March 30, 2017
Bloch oscillations in a one-dimensional spinor gas.
1School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom. d.m.gangardt@bham.ac.uk
Physical Review Letters
|March 5, 2009
Summary
Spin-flipped particles in quantum gases can exhibit Bloch oscillations, but this requires viscous friction. Researchers found friction is absent in integrable systems but weak in near-integrable ones, suggesting Bloch oscillations are observable.
Area of Science:
- Quantum physics
- Condensed matter physics
- Atomic physics
Background:
- Spin excitations in one-dimensional quantum gases can exhibit complex dynamics.
- Bloch oscillations, a quantum mechanical phenomenon, involve periodic motion of wave packets in a crystal lattice or similar periodic potential.
- The role of inter-particle interactions and quantum fluid properties in mediating such oscillations is an active area of research.
Purpose of the Study:
- To investigate the conditions under which a spin-flipped particle in a one-dimensional spinor gas can undergo Bloch oscillations.
- To determine the dependence of Bloch oscillations on the viscous friction force exerted by the surrounding quantum fluid.
- To evaluate this friction in terms of quantum fluid parameters and analyze its behavior in integrable and near-integrable systems.
Main Methods:
- Theoretical evaluation of viscous friction force acting on a spin excitation.
- Analysis of friction in terms of quantum fluid parameters.
- Investigation of specific cases, including SU(2) symmetric gases (bosons and fermions).
- Examination of the friction for small deviations from integrability.
Main Results:
- Bloch oscillations are possible when a viscous friction force is present.
- The viscous friction force is absent in integrable cases, such as SU(2) symmetric gases.
- For systems with small deviations from exact integrability, the friction is very weak.
- This weak friction suggests that Bloch oscillations may be observable in such near-integrable systems.
Conclusions:
- The existence of Bloch oscillations for a spin-flipped particle is critically dependent on the viscous friction from the quantum fluid.
- Integrable systems, like SU(2) symmetric gases, lack the necessary friction, precluding Bloch oscillations.
- Near-integrable systems exhibit weak friction, creating a potential window for observing Bloch oscillations in quantum gases.
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