Related Experiment Video
Updated: Sep 28, 2025
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
9.8K
Decoherence-Induced Exceptional Points in a Dissipative Superconducting Qubit
Weijian Chen1,2, Maryam Abbasi1, Byung Ha1
1Department of Physics, Washington University, St. Louis, Missouri 63130, USA.
Physical Review Letters
|April 1, 2022
Summary
Researchers observed unique quantum system behaviors using superconducting circuits. They identified two types of exceptional points in open quantum systems, leading to novel chiral state transfer and control applications.
Area of Science:
- Quantum Physics
- Quantum Information Science
- Condensed Matter Physics
Background:
- Open quantum systems display complex dynamics from dissipation and coherent evolution.
- These dynamics are mathematically described by a Liouvillian superoperator.
- Exceptional points in the Liouvillian signify critical dynamics in open quantum systems.
Purpose of the Study:
- To experimentally observe and characterize different types of Liouvillian exceptional points.
- To investigate the role of energy loss and decoherence in forming these exceptional points.
- To demonstrate non-Hermiticity-induced chiral state transfer by dynamically tuning the Liouvillian.
Main Methods:
- Utilized a superconducting transmon circuit coupled to an engineered environment.
- Observed Liouvillian exceptional points arising from energy loss and decoherence, or solely decoherence.
- Employed real-time dynamic tuning of Liouvillian superoperators.
Main Results:
- Successfully observed two distinct types of Liouvillian exceptional points.
- Demonstrated non-Hermiticity-induced chiral state transfer through dynamic Liouvillian tuning.
- Provided experimental evidence for the critical dynamics associated with exceptional points.
Conclusions:
- Highlights the significance of Liouvillian exceptional points for understanding open quantum system dynamics.
- Suggests new avenues for applying non-Hermitian dynamics in quantum control and system analysis.
- Motivates a re-examination of open quantum systems through the lens of exceptional points.
Related Concept Videos
01:23Atomic Nuclei: Nuclear Relaxation Processes
745
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.
745
01:24Superconductor
1.3K
A substance that reaches superconductivity, a state in which magnetic fields cannot penetrate, and there is no electrical resistance, is referred to as a superconductor. In 1911, Heike Kamerlingh Onnes of Leiden University, a Dutch physicist, observed a relation between the temperature and the resistance of the element mercury. The mercury sample was then cooled in liquid helium to study the linear dependence of resistance on temperature. It was observed that, as the temperature decreased, the...
1.3K
01:03Atomic Nuclei: Nuclear Spin State Overview
1.2K
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
1.2K
01:04¹³C NMR: ¹H–¹³C Decoupling
1.2K
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...
1.2K
01:28Induced Electric Dipoles
4.4K
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
4.4K
02:32The de Broglie Wavelength
28.3K
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
28.3K