Researchers affiliated with Ames National Laboratory and Iowa State University have achieved a significant breakthrough by observing the manifestation of a Higgs echo within niobium superconductors. This groundbreaking finding offers valuable insights into quantum phenomena that hold considerable promise for the development of next-generation quantum sensing and computing technologies.
Through the application of Higgs echo spectroscopy, Huang et al. identified an unconventional echo formation stemming from disparate broadening and soft quasiparticle bands, which undergo dynamic evolution when subjected to THz excitation. Image courtesy of Ames National Laboratory.
Superconductors are distinguished by their capacity to conduct electricity without any electrical resistance.
Within these superconducting materials exist collective vibrational excitations referred to as Higgs modes.
A Higgs mode represents a quantum mechanical event that occurs when its electron potential undergoes fluctuations analogous to those observed in a Higgs boson.
These modes typically emerge during a material’s transition into a superconducting state.
The detection of these vibrations has historically posed a considerable challenge for the scientific community due to their extremely transient nature.
Furthermore, they exhibit intricate interactions with quasiparticles, which are excitations bearing resemblance to electrons that arise from the disruption of superconductivity.
However, by employing sophisticated terahertz (THz) spectroscopy methodologies, the investigative team has successfully identified a novel category of quantum echo, designated as the Higgs echo, within superconducting niobium—a material integral to quantum computing circuits.
“In contrast to the conventional echoes documented in atomic or semiconductor systems, the Higgs echo originates from an intricate interplay between the Higgs modes and quasiparticles, thereby generating anomalous signals with distinctive attributes,” stated Dr. Jigang Wang, a distinguished researcher at Ames National Laboratory.
“The Higgs echo possesses the capability to retain and elucidate latent quantum pathways inherent within the material.”
By utilizing meticulously timed pulses of THz radiation, the researchers were able to successfully observe these echoes.
Furthermore, through the strategic deployment of these THz radiation pulses, the echoes can be leveraged to encode, store, and retrieve quantum information embedded within this particular superconducting material.
This research underscores the feasibility of controlling and monitoring quantum coherence in superconductors, thereby paving the way for potentially revolutionary approaches to quantum information storage and processing.
“The comprehension and mastery of these distinctive quantum echoes represent a significant stride towards the realization of practical quantum computing and the advancement of sophisticated quantum sensing technologies,” Dr. Wang elaborated.
A research paper detailing this discovery was formally published on June 25th in the esteemed journal Science Advances.
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Chuankun Huang et al. 2025. Discovery of an unconventional quantum echo by interference of Higgs coherence. Science Advances 11 (26); doi: 10.1126/sciadv.ads8740
