Instead of fighting dissipation, they've learned to use it.
In the long human effort to harness the strange intimacy of quantum entanglement, the greatest obstacle has always been the world itself — its noise, its heat, its relentless tendency to dissolve delicate order. A team led by Aziza Almanakly at MIT has now turned that logic on its head, demonstrating that energy loss, long treated as the enemy of quantum coherence, can be engineered into a tool that creates and sustains entanglement. Achieved in superconducting circuits and measured at a Bell-state fidelity of 0.89, this work does not merely improve a technique — it reframes the relationship between fragility and control at the frontier of quantum science.
- Quantum entanglement has always demanded near-impossible precision — one stray fluctuation, one mistimed pulse, and the fragile connection collapses entirely.
- The MIT-led team shattered that assumption by deliberately allowing energy to leak from the system, steering two superconducting artificial atoms into protected 'dark states' that resist certain classes of noise.
- A Bell-state fidelity of 0.89 ±0.02 — surpassing previous methods — was achieved without the hair-trigger calibration that made older approaches brittle and difficult to scale.
- Individual qubits held coherence for 29.5 microseconds, and spectroscopy confirmed strong coupling eight times the initial decay rate, grounding the theory in measurable laboratory reality.
- The path forward remains steep: the approach has only been tested in controlled conditions, and whether it survives the complex, unpredictable noise of real-world quantum systems is still an open question.
For years, quantum physicists have wrestled with a paradox: the more carefully they try to preserve entanglement, the more it escapes them. Standard methods demand microsecond-level calibration and near-perfect isolation from environmental noise — conditions that are difficult to sustain and nearly impossible to scale. A team led by Aziza Almanakly at MIT's Research Laboratory of Electronics, in collaboration with Chalmers University of Technology, has found a way to reframe the problem entirely. Rather than fighting energy loss, they engineered it.
The approach, known as a driven-dissipative protocol, works by allowing energy to leak from a system of two superconducting artificial atoms coupled through a waveguide — but in a controlled, correlated manner. This carefully orchestrated leakage steers the quantum state toward so-called dark states: configurations that are naturally shielded from certain types of noise. A continuous electromagnetic drive sustains the process, removing the need for the precise pulse timing that made earlier methods so fragile.
The results are concrete. The team achieved a Bell-state fidelity of 0.89 ±0.02, a meaningful improvement over previous entanglement methods. Individual qubits maintained coherence for 29.5 microseconds, and transmission spectroscopy revealed coupling eight times stronger than the initial decay rate — confirming that the entanglement was real, robust, and measurable.
The implications reach toward quantum networks, quantum computing scalability, and even quantum sensing, where entangled states sharpen measurement precision. The same principles could potentially be adapted to trapped ions or photonic platforms. Yet the researchers are candid: these results come from a highly controlled laboratory setting. Testing the approach against the messier noise of larger, real-world systems — and extending both the duration and distance of entanglement — remains the work ahead. The gap between a compelling laboratory result and a functioning technology is still wide, but this experiment has meaningfully narrowed it.
For years, quantum physicists have chased a problem that seems almost perverse: the harder they try to hold onto entanglement—that ghostly quantum state where two particles become mysteriously linked—the more it slips away. The standard approach demands exquisite precision. You calibrate your pulses to the microsecond, hold your breath, and hope environmental noise doesn't ruin everything. Now a team led by Aziza Almanakly at MIT's Research Laboratory of Electronics, working with collaborators at Chalmers University of Technology, has found a way to flip the script entirely. Instead of fighting dissipation, they've learned to use it.
The breakthrough centers on a counterintuitive idea: energy loss, normally the enemy of quantum coherence, can actually be engineered to create and preserve entanglement. The team demonstrated this using two giant artificial atoms—superconducting circuits designed to behave as quantum two-level systems—coupled to a waveguide. By applying a continuous electromagnetic drive and carefully orchestrating how energy leaks from the system, they achieved a Bell-state fidelity of 0.89 plus or minus 0.02. That number matters. It represents the quality of the entangled state, a measure of how perfectly correlated the two atoms have become. More importantly, it exceeds what previous methods could accomplish without demanding the kind of hair-trigger calibration that made those older approaches fragile and difficult to scale.
The physics here turns on what researchers call driven-dissipative protocols. Think of it this way: traditional entanglement schemes rely on reversible interactions between qubits, the basic units of quantum information. You have to get the timing exactly right. One mistake, one stray electromagnetic fluctuation from the environment, and the whole thing collapses. The new approach instead uses dissipation strategically. Energy is allowed to leak from the system, but in a controlled, correlated way. This leakage actually steers the quantum state toward what physicists call dark states—protected configurations that are immune to certain types of noise. The waveguide connecting the two artificial atoms acts as a conduit for photons, mediating the entanglement between them. By suppressing individual energy loss while allowing collective dissipation to work, the team preserved the entangled connection.
The experimental results are concrete. Individual qubits maintained coherence for 29.5 microseconds—the duration for which quantum information remains protected from decoherence, a major obstacle in quantum information processing. Transmission spectroscopy revealed a broadened Lorentzian feature eight times wider than the initial decay rate, confirming strong coupling between the artificial atoms and the waveguide and indicating efficient entanglement distribution. These measurements demonstrate that the system works not just in theory but in the lab, under controlled conditions.
What makes this work matter extends well beyond the laboratory. Quantum networks—systems that could transmit information with unparalleled security by leveraging quantum mechanics itself—require reliable, scalable entanglement. Current quantum computing architectures struggle with a fundamental problem: as you add more qubits, maintaining coherence and control becomes exponentially harder. The driven-dissipative approach offers a potential solution. By removing the need for exquisitely calibrated pulses, it could make quantum systems more robust and easier to scale. The implications ripple outward too. The same principles could enhance quantum sensing, where entangled states improve measurement precision, and could be adapted to other physical platforms like trapped ions or photonic systems.
But the researchers are clear about what remains undone. The current results come from a highly controlled laboratory environment. The team has not yet tested whether this approach holds up against the messy, complex noise inherent in larger, real-world quantum systems. Future work will focus on extending how long entanglement can be maintained, increasing the distance over which it can be distributed, and demonstrating robustness against realistic noise conditions. Those are not small challenges. They are the difference between a laboratory curiosity and a technology that actually works in the world.
Citas Notables
By suppressing individual energy loss while allowing collective dissipation to work, the team preserved the entangled connection.— Research findings from Almanakly et al., MIT and Chalmers University
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter that they're using dissipation instead of fighting it? Isn't energy loss always bad in quantum systems?
It is, usually. But these researchers realized that if you engineer the dissipation carefully—if you make it correlated and collective rather than random—it can actually protect the entangled state. It's like using a controlled burn to prevent a wildfire.
So they're not eliminating energy loss. They're steering it.
Exactly. They suppress the energy loss from individual atoms while allowing the system as a whole to leak in a way that preserves the entanglement. The dark states they create are immune to certain types of noise.
What does that Bell-state fidelity number really mean? Why is 0.89 a big deal?
It measures how perfectly correlated the two atoms are. The higher the number, the better the entanglement. 0.89 is high enough that it surpasses previous methods without requiring the kind of microsecond-perfect calibration that made those older approaches fragile.
Does this work outside the lab?
Not yet. That's the honest answer. They've demonstrated it in a highly controlled environment. Whether it survives the noise and complexity of real quantum networks—that's what comes next.
If it does work at scale, what changes?
Everything. Quantum computing becomes more scalable. Quantum networks become feasible. You're no longer fighting against the laws of physics; you're working with them.