Full Breakdown
McGill Researchers Create Quantum Device that Converts Electricity into Phonons at Near-Absolute-Zero
4/29/2026, 12:12:05 PM
Device Converts Electrical Current into Tunable Phonon Bursts
The McGill team built a two-dimensional crystal only a few atoms thick and passed an electric current through it. At temperatures between 10 milli-Kelvin and 3.9 Kelvin, electrons reached speeds above the lattice’s sound speed, emitting phonons in predictable, tunable bursts.
Context: Prior Limits on Phonon Generation
The generation of coherent phonons has been hampered by rapid dissipation and material defects. Earlier work only approached the acoustic threshold, assuming electrons cooled with the lattice. Hilke’s results show electrons can stay energetically “hot” and emit phonons even near absolute zero, challenging existing models.
Team, Partnerships, and Funding
Associate Professor Michael Hilke led the effort at McGill, collaborating with the National Research Council of Canada and using a crystal grown at Princeton University. Funding came from NSERC and Quebec’s Fonds de recherche; results appeared in *Physical Review Letters*.
Key Experimental Parameters
- Architecture: Two-dimensional electron gas in an atomically thin crystal, enabling ultrahigh mobility.
- Temperature: 0.01 K – 3.9 K.
- Electron motion: Collective speeds exceed lattice sound speed, producing resonant magnetophonon emission.
- Material: Crystal minimizes scattering, preserving wave coherence.
Emerging Applications
Phonons travel efficiently through water and tissue, suggesting uses in submarine communication and non-invasive medical imaging or therapy. In quantum computing, vibrational modes could link disparate qubits. The ultimate aim is a phonon laser—a coherent sound source for such environments.
Why It Matters
The ability to generate coherent phonons at cryogenic temperatures opens a new modality for transmitting information where electromagnetic waves fail, potentially reshaping underwater networks, deep-tissue diagnostics, and hybrid quantum systems that require phonon-photon interfacing.
Official Statements & Institutional Responses
Hilke described the device as opening a “new regime of energy conversion inside advanced materials,” with implications for communication, biomedicine and quantum technologies. Funding bodies hailed the work as a frontier exploration of quantum electronics aligned with national research priorities.
Verbatim Quotes
- “Modern communication is largely based on light, including electromagnetic waves and electrical currents. In a medium such as oceans, sound can travel, whereas light and electrical currents cannot,” — Michael Hilke, Associate Professor of Physics, McGill University
- “In the human body, sound waves can also be a useful tool,” — Michael Hilke
- “At absolute zero temperatures, that is, the world of quantum physics, no sound is created unless electrons travel collectively at the speed of sound or above,” — Michael Hilke
- “Phonons have eluded controlled generation for decades. By pushing our devices’ electron speeds past the speed of sound, we’ve uncovered a new regime of energy conversion inside advanced materials. This technology could redefine how we harness and manipulate waves and particles across multiple scientific disciplines.” — Michael Hilke
Next Steps
The group will test graphene and other two-dimensional materials to boost mobility, then scale the phonon source into prototype communication and diagnostic devices, moving toward a practical phonon laser.
