Related Experiment Video
Updated: Mar 9, 2026
09:23
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
15.1K
Observing coherence effects in an overdamped quantum system.
Y-H Lien1,2, G Barontini1,2, M Scheucher1,3
1Centre for Cold Matter, Imperial College, Prince Consort Road, London SW7 2BW, UK.
Nature Communications
|December 22, 2016
Summary
Normal-mode splitting in optical cavities coupled to atoms can occur even without strong coupling, depending on the probing method. This study reveals an avoided crossing in reflection spectra, unlike cavity emission measurements.
Area of Science:
- Quantum optics
- Cavity quantum electrodynamics
Background:
- Optical cavities coupled to atomic media typically require strong coupling for normal-mode splitting.
- Strong coupling is defined as the coherent coupling rate exceeding individual decay rates.
Purpose of the Study:
- To demonstrate that normal-mode splitting in coupled atom-cavity systems is not solely dependent on the strong coupling condition.
- To investigate the influence of probing techniques on the observed spectral features.
Main Methods:
- Utilizing an overdamped optical cavity coupled to an atomic medium.
- Measuring the reflection spectrum of a probe laser from the cavity's input mirror.
- Comparing reflection measurements with measurements of Purcell-enhanced cavity emission.
Main Results:
- An avoided crossing was observed in the reflection spectrum, indicating a form of normal-mode splitting.
- This spectral feature was absent when measuring the cavity's emission spectrum.
- The findings suggest a dependence of spectral behavior on the measurement protocol.
Conclusions:
- Normal-mode splitting in coupled atom-cavity systems can be observed under conditions other than the conventional strong coupling regime.
- The choice of measurement technique (reflection vs. emission) significantly impacts the observed spectral response.
- The phenomenon can be formally understood by analogy to electromagnetically induced transparency.
Related Concept Videos
01:20Types of Damping
7.9K
If the amount of damping in a system is gradually increased, the period and frequency start to become affected because damping opposes, and hence slows, the back and forth motion (the net force is smaller in both directions). If there is a very large amount of damping, the system does not even oscillate; instead, it slowly moves toward equilibrium. In brief, an overdamped system moves slowly towards equilibrium, whereas an underdamped system moves quickly to equilibrium but will oscillate about...
7.9K
01:07Damped Oscillations
7.4K
In the real world, oscillations seldom follow true simple harmonic motion. A system that continues its motion indefinitely without losing its amplitude is termed undamped. However, friction of some sort usually dampens the motion, so it fades away or needs more force to continue. For example, a guitar string stops oscillating a few seconds after being plucked. Similarly, one must continually push a swing to keep a child swinging on a playground.
Although friction and other non-conservative...
Although friction and other non-conservative...
7.4K
01:04Oscillations about an Equilibrium Position
7.1K
Stability is an important concept in oscillation. If an equilibrium point is stable, a slight disturbance of an object that is initially at the stable equilibrium point will cause the object to oscillate around that point. For an unstable equilibrium point, if the object is disturbed slightly, it will not return to the equilibrium point. There are three conditions for equilibrium points—stable, unstable, and half-stable. A half-stable equilibrium point is also unstable, but is named so...
7.1K
02:45The Quantum-Mechanical Model of an Atom
60.7K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
60.7K
01:23Stability of Equilibrium Configuration
858
Understanding the stability of equilibrium configurations is a fundamental part of mechanical engineering. In any system, there are three distinct types of equilibrium: stable, neutral, and unstable.
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
858
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.7K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.7K