Polariton Superfluid Past an Obstacle: A Quantum Phenomenon…

What Polariton Superfluidity Is

A polariton is a quasiparticle that arises from the strong coupling between excitons (bound electron-hole pairs) and photons in semiconductor microcavities. In driven-dissipative systems, these polaritons can form a Bose-Einstein condensate known as an exciton-polariton condensate or superfluid. This state exhibits macroscopic quantum coherence and zero viscosity at low flow velocities.

The simulation demonstrates how this superfluid behaves when encountering an obstacle, transitioning from frictionless superfluid flow to turbulent vortex wakes above the Landau critical velocity.

Why It Happens

As polaritons flow past an obstacle, their interactions and collective behavior lead to a transition from superfluidity to turbulence. This transition is governed by the balance between the coherent pumping of polaritons into the system and the dissipative effects that arise when they interact with the obstacle.

Above the Landau critical velocity, the energy dissipation due to collisions with the obstacle overcomes the coherence maintained by the pump, resulting in turbulent flow patterns.

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Real-World Applications

Understanding polariton superfluidity and its transition to turbulence is crucial for developing novel quantum technologies. These include ultrafast optical switches, quantum information processing devices, and new forms of photonic integrated circuits.

The study of these phenomena also provides insights into the broader field of condensed matter physics, particularly in the context of driven-dissipative systems.

Key Parameters

In the simulation, various parameters such as flow velocity, polariton-polariton interaction strength, obstacle potential height, and coherent pump amplitude can be adjusted. These parameters control the dynamics of the polaritons and their behavior in the presence of an obstacle.

By manipulating these controls, one can observe how changes in each parameter affect the transition from superfluid to turbulent flow.

Frequently asked questions

What is a polariton?

A polariton is a quasiparticle that results from the strong coupling between excitons and photons in semiconductor microcavities, exhibiting quantum mechanical properties of both particles and waves.

How does superfluidity differ from normal fluid flow?

Superfluidity refers to a state where a fluid flows without viscosity, meaning it can flow around obstacles with no energy loss. In contrast, normal fluids experience friction and dissipate energy when flowing past an obstacle.

What is the Landau critical velocity in this context?

The Landau critical velocity marks the threshold at which a polariton superfluid transitions from a state of zero viscosity to one where turbulence sets in due to increased dissipation and interactions with the obstacle.

Why are exciton-polaritons important for quantum technologies?

Exciton-polaritons offer unique opportunities for quantum information processing, as they can be used to create entangled states and perform operations at ultrafast timescales, making them valuable for developing new types of quantum devices.

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Everything above runs in your browser — open Polariton Superfluid Past an Obstacle and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

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