3 articles · Updated · The Quantum Insider · Jun 16
Summary
A single electron trapped above superfluid helium reached the strong-coupling regime with a microwave resonator, letting it exchange energy coherently with a photon fast enough for quantum control.
The team measured a 118 MHz coupling rate, above the resonator linewidth of 23 MHz and the electron decoherence rate of 61 MHz, and confirmed the result through vacuum Rabi splitting.
Using a high-impedance superconducting resonator and a compact helium-based electron trap at 7 millikelvin, researchers also showed deterministic loading and unloading of individual electrons and mapped their motional states with two-tone spectroscopy.
Coherence remains the main obstacle: excited-state lifetimes approached 0.76 microseconds, but pure dephasing dominated losses and worsened sharply as temperature rose toward 450 millikelvin.
The result gives electron-on-helium devices a key building block for future spin readout and scalable qubit designs, though the source of dephasing and multi-qubit integration still need to be solved.
Can a lone electron on liquid helium outperform the quantum computers built by today's tech giants?
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EeroQ’s 118 MHz Strong Coupling Milestone: Paving the Way for CMOS-Compatible Quantum Computers
Overview
EeroQ Corporation has reached a major milestone in quantum computing by demonstrating strong coupling between the motional state of an electron in a quantum dot and an on-chip microwave resonator. This achievement, published on nature.com, marks a critical advancement for the electron-on-helium (eHe) platform, positioning it as a promising foundation for future quantum computers. EeroQ’s experiments, which involved embedding the resonator within a microfluidic device, showcased precise engineering and control over quantum systems. These results highlight the potential of the eHe platform to enable scalable and robust quantum computing technologies.