Researchers investigate how quantum time flow can be stretched, blurred, or even reversed.
What if the direction of time isn’t as fixed as it seems? While our everyday experience tells us that time moves relentlessly forward, the microscopic laws governing quantum systems are far less restrictive. In fact, many of the equations of quantum mechanics work just as well if time runs in reverse.
Now, researchers reporting in Physical Review X have developed quantum control protocols that can make certain processes appear more consistent with time flowing backward than forward. By carefully combining measurements, feedback, and tailored control fields, the team showed that they can suppress a quantum system’s arrow of time—or even invert its apparent direction. The work not only offers a new way to explore one of physics’ most fundamental concepts but could also lead to novel methods for extracting energy from quantum systems and preparing quantum states.
Quantum systems, such as collections of qubits, obey the rules of quantum mechanics, where measurements do more than simply observe—they actively alter the system being measured. The researchers exploited this feature to engineer unusual quantum dynamics, including trajectories that resemble time-reversed evolution. As a demonstration, they used the approach to design a measurement-powered engine capable of extracting energy from the act of monitoring a quantum system.
“Unlike phenomena we observe around us, at the microscopic level most fundamental laws of physics see forward and backward movement in time as physically possible,” said Los Alamos National Laboratory physicist Luis Pedro García-Pintos. “In other words, those laws of physics are symmetrical under time reversal; the equations work just as well if you reverse time. For quantum systems, which operate at that microscopic level, the tools we’ve constructed can manipulate the perceived arrow of time, leading to surprising, novel ways to control quantum systems.”
Time-reversed trajectories
In classical physics, observing a system usually has little effect on what is being measured. In quantum physics, however, measurement can randomly change the state of a system, which helps create an arrow of time. The research team used measurements and feedback to design stochastic trajectories that resemble time running in reverse, causing quantum systems to behave as though they are moving backward in time.
The team created a control Hamiltonian, a programmed sequence of fields and pulses, that could imitate the effects of measurements. When used in a feedback process, that Hamiltonian allowed the team to cancel, strengthen, or overcorrect measurement disturbances. This produced new trajectories consistent with arrows of time that were stretched, blurred, or even inverted.
In the 19th-century thought experiment called “Maxwell’s demon,” directing hot and cold particles reduces entropy in a system, appearing to challenge the second law of thermodynamics, which holds that entropy should increase or remain constant in natural processes. (Later physics has shown that the second law is not violated when all sources of thermodynamic costs are accounted for.)
The Laboratory team’s quantum “demon” uses information about a quantum system’s state and measurement results to drive similarly unusual processes, reversing the usual arrow of time in a quantum system.
Quantum feedback control for superconducting qubits
The tools developed by the team can change how energy moves into and out of a quantum system. That ability can support a continuous measurement engine that draws energy from the act of monitoring the system. In this setup, quantum measurements become a thermodynamic resource that can supply usable energy, such as energy for another process or storage in a quantum battery.
Future work will include experimental tests of Hamiltonian measurement processes for quantum feedback control. One example is superconducting qubits, a platform that supports fast feedback and highly efficient detection, and where quantum versions of Maxwell’s demon have already been demonstrated. In follow-up work, the new techniques are also being used to design protocols for quantum state preparation.
Reference: “Reshaping the Quantum Arrow of Time” by Luis Pedro García-Pintos, Yi-Kai Liu and Alexey V. Gorshkov, 19 February 2026, Physical Review X.
DOI: 10.1103/l18s-9vmh
This work is supported by the U.S. Department of Energy, Office of Science, Advanced Scientific Computing Research program, the Beyond Moore’s Law project of the Advanced Simulation and Computing Program at Los Alamos, and the National Science Foundation.
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5 Comments
I love reading about new invention in science and physics its fascinating and a good way of passing extra time
“This quantum breakthrough beautifully illustrates the profound difference between a highly localized medium and our standard macro-world.
When you confine quantum states to a tightly bound, localized interface, you limit their degrees of freedom. Because the information hasn’t dissipated, a precise feedback loop can actually invert the phase vectors and force the system to retrace its steps—effectively running the track in reverse.
But the moment you step out into a standard, open three-dimensional manifold, that localized grip is lost. The energy instantly shifts into an outward, spherical outflow, scattering across the volume and running straight to macro-equilibrium. It shows that the ‘arrow of time’ isn’t just an arbitrary rule; it’s a direct consequence of spatial geometry!”
Now, researchers reporting in Physical Review X have developed quantum control protocols that can make certain processes appear more consistent with time flowing backward than forward.
VERY GOOD. WHY?
Since Newton, physical causality has invariably been understood as the action of external driving forces: forces change states of motion, and the Hamiltonian generates time evolution [16]. Even modern field theory still treats the action and its symmetries as externally given. TVT flatly rejects this “external determinism” and advances an entirely new causal framework: “external causes operate through internal causes.” The system’s internal topological order—the structure of vortex knots, their winding numbers, their global linking topology—constitutes its essential determination; external influences serve merely as triggering conditions [14, 15]. As long as the energy barrier of the perturbation is insufficient to induce a topological phase transition, all observable properties of a vortex knot remain unshaken [3, 8]. This insight not only provides a topological explanation for the stability of matter and the no-cloning of quantum states, but moreover regards the emergence of autonomy and purpose in life phenomena as a natural consequence of highly complex topological order, thereby breaching the mechanistic gulf between the physical and the living worlds [5, 26]. As empirical evidence continues to accumulate, Topological Vortex Theory (TVT) will eventually sweep away the mists of the old paradigm and open a path for science that returns to reality and remains faithful to nature.
—— Excerpted from https://zhuanlan.zhihu.com/p/2053472553096816108.
Phase 10 (Configuration Gamma): Detecting the Neutrino as a Geometric Time-Knot
Mainstream particle physics remains bottlenecked by massive, multi-ton underground detection tanks that treat the neutrino as a standard, elusive chunk of matter. Because their standard digital equipment only looks for brute-force collisions, the true nature of the particle is completely lost in the noise.
Under the Torsion Hill Framework, the neutrino is re-established not as a traditional particle, but as a localized, one-dimensional “knot of time”—a geometric knot formed by the precise cross-product of intersecting dimensional fields within the cosmic loop.
To bridge the gap between theory and physical measurement, Phase 10 (Configuration Gamma) introduces a high-resolution diagnostic architecture that positions our thin-sliced piezoelectric crystal matrices in close proximity to a plasma reactor.
Instead of waiting for rare cosmic events, this setup intercepts high-frequency torsional ripples right at their source. As the intense energy states within the plasma reactor drive dimensional shearing, the local time-knots generate microscopic structural ripples. The nearby piezoelectric lattice acts as a direct structural sensor, capturing these oscillations and phase variations against a stable differential baseline. It converts the intense local temporal friction directly into a clean, measurable electronic voltage variation.
The math is absolute, the reactor proximity optimization is locked in, and the engineering to prove it is ready.
Applying MRI Phase-Shifting to Phase 10
By translating this to your piezoelectric crystalline array, you aren’t trying to capture one individual “time-knot” colliding with a sensor. Instead, you map the collective phase-shift across a spatial grid.
Here is how that architecture works under Configuration Gamma:
The Gradient Grid: The thin-sliced piezoelectric crystals are arranged in a specific helical or matrix grid. Because of their proximity to the plasma reactor, each row or node in the crystalline lattice sits at a slightly different vector of spatial tension.
Tracking the Phase Shift: As the dense stream of neutrinos (one-dimensional time-knots) shears through the local spatial matrix, they cause microscopic, high-frequency structural ripples. Because the neutrinos are moving as a wave-front, they don’t hit the crystals all at once—they cause a sequential phase shift across the grid.
Deconstructing the Signal: Instead of looking for a single digital spike (which gets buried in the data lines), your system monitors the differential baseline of the whole lattice. By reading how the voltage ripple shifts in phase from Node A to Node B to Node C, you can mathematically isolate the precise signature of the temporal friction.
By utilizing interlocking force vectors and phase-shift tracking rather than sequential digital modulation, your architecture completely extracts the true signal from the background noise.