Study Reveals Heating Source in Quantum Dot Qubits via Two-Level Fluctuators

Researchers at the University of Rochester have, for the first time, identified the source of heat generated in quantum dot qubits—a major obstacle to building more powerful quantum computers. Published in Physical Review Applied on February 13, 2026, the study by Feiyang Ye, Lokendra S. Dhami, and John M. Nichol reveals that voltage pulses used to operate these qubits cause heating linked to two-level fluctuators within silicon quantum dots.

The team observed that these pulses increase the switching rates and occupation biases of the fluctuators, with the amount of heating dependent on pulse amplitude, frequency, and gate voltage. This suggests that electrons accumulating near the gates contribute to the problem, leading the researchers to hypothesize that reducing gate area could mitigate the unwanted heat; as stated in the research, the team hopes to “reduce the area of the gates with electrons nearby.” A surprising link between voltage pulses and localized heating is undermining efforts to build stable silicon quantum computers. Researchers at the University of Rochester and the University of Rochester Center for Coherence and Quantum Science have discovered that the very pulses used to control spin qubits in silicon quantum dots are generating unwanted heat, impacting performance.

The team’s investigation, published on February 13, 2026, focused on charged two-level fluctuators (TLFs) within the quantum dots, revealing a previously unknown source of decoherence. Specifically, they observed that “voltage pulses on nearby gates tend to increase TLF switching rates and occupation biases.” This heating isn’t simply a matter of distance; the amount of heat generated doesn’t change based on how far the pulsed gates are from the TLFs. Instead, the magnitude of heating is linked to both the pulse amplitude and frequency, as well as the “idling voltage of the pulsed gates,” suggesting accumulated electrons play a key role. John M. The pursuit of stable quantum computation in silicon has increasingly focused on understanding and mitigating sources of qubit decoherence, with recent attention turning to the impact of voltage pulses necessary for qubit control. While essential for initialization, gate operation, and readout, these pulses generate heat that subtly shifts qubit frequencies and diminishes the precision of quantum gates. Importantly, the magnitude of this heating isn’t dictated by the physical distance between the pulsed gates and the TLFs, but rather by the characteristics of the pulses themselves. John M. To encode quantum information in semiconductor spin qubits, voltage pulses are necessary for initialization, gate operation, and readout. The research indicates that the idling voltage of the gates—the voltage maintained when not actively switching qubits—plays a crucial role, leading John M. This understanding is vital as voltage pulses are “necessary for initialization, gate operation, and readout” of spin qubits. Source: http://link.aps.org/doi/10.1103/1fz7-tjq8 Tags: Quantum News There is so much happening right now in the field of technology, whether AI or the march of robots. Adrian is an expert on how technology can be transformative, especially frontier technologies. But Quantum occupies a special space. Quite literally a special space. A Hilbert space infact, haha! Here I try to provide some of the news that is considered breaking news in the Quantum Computing and Quantum tech space. Latest Posts by Quantum News: AQT Arithmos Quantum Technologies Launches Real-World Testing Program, Starting March 31, 2026 February 19, 2026 Rigetti Computing Announces Date for Q4 & Full-Year 2025 Financial Results February 19, 2026 Quantonation Closes €220M Fund, Becoming Largest Dedicated Quantum Investment Firm February 19, 2026