To celebrate the International Year of Quantum Science and Technology, Physical Review X is compiling a list of groundbreaking papers it has published in the quantum arena. Each month we will highlight a selection of papers from different topic areas, showcasing the remarkable depth and breadth of quantum developments featured in Physical Review X.
Measurement-induced quantum phase transitions
Quantum computing schemes rely on maintaining entanglement between a large number of components. Measurements on a quantum system impact on and limit entanglement properties. Large quantum systems turn out to have phase transitions in their entanglement structure that depend on the rate of measurement [1]. They are driven by a competition between a quantum system’s internal evolution and the external observations. Such transitions are not visible in standard quantum mechanical observables due to the randomness of the measurement outcomes. They thus require new tools for their diagnosis [2], and novel theoretical approaches for their description [3]. Developing an understanding of such general non-unitary dynamics is a crucial stepping stone for the development of quantum technologies.
- [1] B. Skinner, et al., “Measurement-induced phase transitions in the dynamics of entanglement ”, Phys. Rev. X 9, 031009 (2019)
- [2] M. J. Gullans and D. A. Huse, “Dynamical purification phase transition induced by quantum measurements ”, Phys. Rev. X 10, 041020 (2020)
- [3] M. Buchold, et al., “Effective theory for the measurement-induced phase transition of Dirac fermions ”, Phys. Rev. X 11, 041004 (2021)
Erasure conversion: theory and experiment
Overcoming errors is one of the biggest challenges in quantum computing, as noise inevitably disrupts quantum operations. Quantum error correction provides a solution, but at a steep cost: a massive overhead in the number of physical qubits required to encode information. A promising way to mitigate this challenge is through erasure conversion: designing qubits so that their most common error-qubit loss-is significant yet easily detected, located, and corrected. By lowering the resources required for error correction and reducing fault-tolerance thresholds, erasure conversion offers a practical path toward scalable quantum computation. The PRX editors want to share their enthusiasm for major advances in this field, showcasing both theoretical breakthroughs and experimental demonstrations in superconducting qubits [4,5] and neutral atoms [6].
- [4] A. Kubica, et al., “Erasure qubits: overcoming the T1 limit in superconducting circuits” , Phys. Rev. X 13, 041022 (2023)
- [5] H. Levine, et al., “Demonstrating a long-coherence dual-rail erasure qubit using tunable transmons” , Phys. Rev. X 14, 011051 (2024)
- [6] K. Sahay, et al., “High-threshold codes for neutral atom qubits with biased erasure errors” , Phys. Rev. X 13, 041013 (2023)
Quantum algorithms for quantum simulation
Simulating quantum systems has long been one of the most anticipated applications of quantum computing. The promise is to tackle problems that scale exponentially on classical computers—such as modeling correlated quantum matter and chemical reactions at the electronic level. Unlike classical approaches, which quickly become intractable as system size grows, quantum devices have the potential to perform these simulations with polynomial resources. But realizing this vision on today’s imperfect, small-scale quantum hardware demands new algorithmic strategies that are both efficient and resilient.
In this collection, we showcase recent studies that demonstrate how far the field has come: chemically accurate quantum simulations achieved directly on superconducting processors [7] ; hybrid quantum-classical protocols that mitigate noise through extrapolation techniques [8] ; and a powerful new theoretical framework that tightly bounds Trotter errors across a broad class of models [9].
Advancing quantum algorithms toward problems of practical importance is now a central goal of the quantum information community. The PRX editors are pleased to highlight these three articles as important steps toward making quantum computing a transformative tool for real-world scientific discovery.
- [7] P. J. J. O’Malley, et al., “Scalable quantum simulation of molecular energies” , Phys. Rev. X 6, 031007 (2016)
- [8] Y. Li and S. C. Benjamin, “Efficient variational quantum simulator incorporating active error minimization” , Phys. Rev. X 7, 021050 (2017)
- [9] A. M. Childs, et al., “Theory of Trotter error with commutator scaling” , Phys. Rev. X 11, 011020 (2021)
Mid-circuit measurements with cold atoms
A central challenge in building quantum computers is the need to monitor and correct fragile quantum states—without collapsing the system in the process. Mid-circuit measurements offer a powerful solution: the ability to extract targeted information during a computation while preserving coherence and enabling real-time feedback. Long thought to be out of reach for neutral atom platforms, these capabilities have now been brought to life in a series of experiments. This collection highlights three pioneering advances that demonstrate midcircuit measurements for neutral atom systems. With slightly different protocols, the studies achieve state- or site-selective readout on “ancilla qubits” while preserving the quantum coherence of the “data qubits” [10,11,12]. The PRX editors are pleased to highlight these contributions as major steps toward scalable and controllable quantum technologies.
- [10] M. A. Norcia, et al., “Midcircuit qubit measurement and rearrangement in a 171Yb atomic array”, Phys. Rev. X 13, 041034 (2023)
- [11] J. W. Lis, et al., “Midcircuit operations using the omg architecture in neutral atom arrays” , Phys. Rev. X 13, 041035 (2023)
- [12] T. M. Graham, et al., “Midcircuit measurements on a single-species neutral alkali atom quantum processor” , Phys. Rev. X 13, 041051 (2023)
Quantum spin liquids
Quantum spin liquids are an exotic state of matter, which was originally proposed as the ground state for some frustrated quantum antiferromagnets. They are expected to display a wide array of intriguing properties, including long-range quantum entanglement and fractionalized excitations, while at the same time not spontaneously breaking any symmetry. In recent years, spin liquids have been subject of many investigations, both theoretical and experimental.
In this Collection, the PRX editors are proud to display some of the most important studies on quantum spin liquids published in PRX. Through extensive numerical simulations, it was shown that a spin liquid ground state is to be expected on two-dimensional triangular lattices [13], as well as in the presence of some peculiar quantum critical points [14]. While spin liquid behavior is very hard to confirm experimentally, promising signatures have been observed in quasi-two dimensional materials [15] and in some pyrochlores [16]. While these are impressive achievements, we believe many more exciting results are yet to come, and we look with enthusiasm at the future of this field.
- [13] A. Szasz, et al., “Chiral spin liquid phase of the triangular lattice Hubbard model: a density matrix renormalization group study”, Phys. Rev. X 10, 021042 (2020)
- [14] W.-Y. Liu, et al., “Emergence of a gapless quantum spin liquid from deconfined quantum critical point” , Phys. Rev. X 12, 031039 (2022)
- [15] E. Lefrancois, et al., “Evidence of a phonon Hall effect in the Kitaev spin liquid candidate α-RuCl3” , Phys. Rev. X 12, 021025 (2022)
- [16] E. M. Smith, et al., “Case for a U(1)π quantum spin liquid ground state in the dipole-octupole pyrochlore Ce2Zr2O7” , Phys. Rev. X 12, 021015 (2022)
- [17] A. Seri, et al., “Quantum correlations between single telecom photons and multimode on-demand solid-state quantum memory ”, Phys. Rev. X 7, 021028 (2017)
- [18] D. Buterakos, et al. “Deterministic generation of all-photonic quantum repeaters from solid-state emitters ”, Phys. Rev. X 7, 041023 (2017)
- [19] M. Buchold, et al.. “One-way quantum repeater based on near-deterministic photon-emitter interfaces ”, Phys. Rev. X 10, 021071 (2020)
- [20] M. S. Rudner, et al., “Anomalous edge states and the bulk-edge correspondence for periodically driven two-dimensional systems ”, Phys. Rev. X 3, 031005 (2013)
- [21] N. Goldman and J. Dalibard, “Periodically driven quantum systems: Effective hamiltonians and engineered gauge fields ”, Phys. Rev. X 4, 031027 (2014)
- [22] L. D'Alessio and M. Rigol, “Long-time behavior of isolated periodically driven interacting lattice systems ”, Phys. Rev. X 4, 041048 (2014)
- [23] V. S. Denchev, et al., “What is the computational value of finite-range tunneling? ”, Phys. Rev. X 6, 031015 (2016)
- [24] K. M. Sliwa, et al., “Reconfigurable Josephson circulator/directional amplifier ”, Phys. Rev. X 5, 041020 (2015)
- [25] A. Narla, et al., “Robust concurrent remote entanglement between two superconducting qubits ”, Phys. Rev. X 6, 031036 (2016)
- [26] E. Suguru, et al., “Practical quantum error mitigation for near-future applications”, Phys. Rev. X 8, 031027 (2018)
- [27] B. Koczor “Exponential error suppression for near-term quantum devices”, Phys. Rev. X 11, 031057 (2021)
- [28] W. J. Huggins, et al., “Virtual distillation for quantum error mitigation”, Phys. Rev. X 11, 041036 (2021)
- [29] C. E. Bradley, et al., “A ten-qubit solid state spin register with quantum memory up to one minute”, Phys. Rev. X 8, 031045 (2019)
- [30] V. V. Albert, et al., “Robust encoding of a qubit in a molecule”, Phys. Rev. X 10, 031050 (2020)
- [31] Y. Sung, et al., “Realization of high-fidelity CZ and ZZ-free iSWAP gates with a tunable coupler”, Phys. Rev. X 11, 021058 (2021)
- [32] S. A. Moses, et al., “A race-track trapped-ion quantum processor”, Phys. Rev. X 13, 041052 (2021)
- [33] C. Mordini, et al., “Multizone trapped-ion qubit control in an integrated photonics QCCD device”, Phys. Rev. X 15, 011040 (2025)
- [34] K. E. Castoria, et al., “Sensing and control of single trapped electrons above 1K”, Phys. Rev. X 15, 041002 (2025)
- [35] J. A. Muniz, et al., “Repeated ancilla reuse for logical computation on a neutral atom quantum computer”, Phys. Rev. X 15, 041040 (2025)
- [36] L. A. Lessa, et al., “Mixed-state quantum anomaly and multipartite entanglement”, Phys. Rev. X 15, 011069 (2025)
- [37] Nicolò Beato, et al., “Toward a theory of phase transitions in quantum control landscapes”, Phys. Rev. X 15, 041014 (2025)
Quantum communication
Efficiently transmitting quantum states between distant devices is one of the central challenges in building quantum communication networks. Since it is not possible to create copies of arbitrary quantum states, sending them over long distances requires the development of quantum memories and repeaters which have no classical counterparts.
In this Collection, the editors of PRX are proud to highlight some of the most important milestones in the development of quantum communication infrastructure: the development of solid state based quantum memories to store photons [17], and the theoretical proposals of protocols and architectures to implement a network of quantum repeaters [18,19]. We look with excitement at the future of this field.
Floquet systems
Controlling the behavior of quantum systems far from equilibrium has become a central challenge in modern physics and quantum technologies. A powerful strategy to achieve this control is Floquet engineering, which uses time-periodic driving to stabilize quantum phases, tune interactions, or even induce topological order. By modulating systems in time rather than space, Floquet techniques unlock behaviors not accessible in static settings, enabling the realization of designer Hamiltonians in platforms ranging from ultracold atoms to solid-state systems.
In this Collection, the editors of PRX are proud to highlight three pioneering contributions that helped define this field. One study explains how periodic driving can completely change the topological behavior of a system, and can be used to induce robust and controllable edge currents [20]. Another introduces a controlled protocol to engineer synthetic spin-orbit coupling and gauge fields in cold atom systems [21]. A third shows that, at long times, periodically driven interacting systems can behave as if governed by random Hamiltonians drawn from specific ensembles [22]. More than a century after Gaston Floquet first explored how periodic forces shape classical dynamics, we are now looking with excitement toward the future of Floquet quantum matter!
2025 Nobel Prize in Physics
This year, the Nobel Prize in Physics has been awarded to John Clarke, Michel H. Devoret, and John M. Martinis “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit”. The editors of PRX extend to all three new laureates our most heartfelt congratulations, and are proud to highlight in this Collection some of their contributions that have been published in our journal.
In one study, Prof. Martinis and collaborators showed that quantum tunneling allows for a significant speedup in the solution of optimization problems [23]. Meanwhile, Prof. Devoret and his group realized in [24] a superconducting circuit that can be used as either a circulator or a directional amplifier, and in [25] demonstrated how superconducting qubits can be entangled remotely. It is our honor to have published these results, and we look forward to the exciting future of superconducting quantum devices.
Quantum error mitigation
In order for their computations to be reliable, quantum devices need to be protected from environmental noise. For current quantum devices, which are too small to allow for quantum error correction to be used, various methods have been developed to minimize the impact of noise on quantum computations, in order to enhance their reliability.
In this Collection, we highlight some of the most influential contributions to the field of quantum error mitigation techniques. In [26], it is shown how noise can be reduced even with imperfect knowledge of its structure. In [27], the author shows how exponential suppression of the noise can be achieved even for large system sizes. Finally, in [28] it is explained how running multiple copies of a quantum algorithm can dramatically reduce errors. These ideas have been crucial in the development of the state of the art quantum devices, and we are proud to showcase them.
Physical platforms for quantum information processing
Diverse experimental platforms for quantum information processing are being rapidly developed by research groups worldwide. PRX has proudly published some of the most important advancements they have made. This Collection showcases four landmark results that represent significant leaps in the stability, control, and scalability of quantum hardware.
The featured works span a variety of physical architectures, each addressing critical hurdles in the field. For solid-state systems, [29] demonstrates multi-qubit registers capable of long-term, decoherence-protected information storage. In the realm of molecular physics, [30] proposes a method for encoding qubits in rotational states to make them less susceptible to error. For superconducting circuits, [31] introduces a high-fidelity gate implementation essential for reliable computation. Finally, [32] presents a one-dimensional trapped-ion processor design that incorporates the architectural features necessary for scaling to large-size devices.
Looking towards the future
In the final installment of this Collection, the editors of PRX are proud to highlight several compelling contributions published during the 2025 International Year of Quantum. These works underscore PRX’s ongoing commitment to publishing highly impactful research in quantum science and technology.
On the experimental and technological side, three papers demonstrate the rapid progress toward high-fidelity operation and detection of large-scale qubits across diverse platforms. These include trapped ions divided into multiple zones [33], single electrons above the surface of liquid helium [34], and neutral atoms in arrays of optical tweezers [35].
Complementing these technological leaps, the theoretical works in this selection bridge fundamental concepts with new applications: [36] explores the connection between mixed-state entanglement and quantum anomalies, while [37] introduces a framework to study phase transitions in quantum control protocols. These contributions reflect the richness of the field, pointing toward a vibrant future for quantum innovation.
A new model of qubit noise that is motivated by neutral atom qubits leads to much higher rates of error correction in tailored error-correcting codes.
Researchers have realized a recently proposed qubit in which the errors mostly involve erasure of the qubit state, an advance that could help simplify the architecture of fault-tolerant quantum computers.
A simple scheme to convert amplitude-damping noise in superconducting circuits to easier-to-correct heralded erasure noise overcomes conventional limits on quantum information fidelity.
The growth of entanglement in a quantum system changes qualitatively when it is observed more frequently than a certain critical rate, an important insight for describing quantum systems computationally.
The rate at which a many-body quantum system is measured can induce a transition between a state that remembers initial conditions and one that forgets, possibly leading to new types of quantum error-correcting codes.
A new theory of measurement-induced phase transitions reveals the effective degrees of freedom at the transition, which capture the structural change in the wave function at large distances and describes the transition in macroscopic observables.
Product formulas offer a powerful, simple approach to quantum simulation. A new theory quantifying their errors puts these algorithms on a rigorous foundation, showcasing their superiority over other methods.
A quantum computer is used to efficiently model a quantum chemical system to extremely high accuracy.
Quantum computers will need to be tolerant to errors introduced by noise, but current proposals estimate that the number of qubits required for error correction will be many orders of magnitude larger than the number needed for useful computation. A new proposal uses a classical-quantum hybrid scheme to implement simple error-tolerant quantum processors with relatively few resources.
Three research groups have exploited the nuclear spins of ytterbium-171 to manipulate qubits before they are read out—an approach that could lead to efficient error-correction schemes for trapped-atom computing platforms.
Three research groups have exploited the nuclear spins of ytterbium-171 to manipulate qubits before they are read out—an approach that could lead to efficient error-correction schemes for trapped-atom computing platforms.
Shelving data qubits in protected hyperfine states while measuring an ancilla qubit allows for robust midcircuit measurements in a neutral atom array, a key step toward extending the lifetime of atomic quantum memories.
A chiral spin liquid—in which heat moves in one direction around the edge of the material—arises in a simple model of a prototypical quantum spin liquid, answering long-standing questions about these exotic states of matter.
An analysis of a common theoretical model of antiferromagnetic interactions reveals the deep relationship between two pillars of condensed-matter physics: quantum spin liquids and deconfined quantum critical points.
Thermal Hall conductivity measurements attribute heat conduction in one spin liquid candidate to phonons scattering off spins and find no evidence for predicted Majorana fermions.
By measuring how Ce spins interact in CeZrO, new experimental work lays out a detailed case for a novel quantum spin liquid phase at low temperature in this material.
Crystals with rare-earth ions could lead to quantum repeaters that enable secure quantum communications over long distances.
Quantum repeaters allow for reliable transmission of quantum information over long distances. One possible approach relies on highly entangled photons. A new protocol provides a way to generate arbitrarily large states of entangled photons using just one emitter coupled to a single qubit.
A proposed protocol for a one-way quantum repeater could enable robust long-distance quantum communication with significantly fewer resources than other proposals.
The periodic input of energy into systems—driving—can have profound effects. Scientists studying driven interacting quantum systems find that a lattice model displays three different regimes as a function of driving period.
Topological effects can result from a material’s intrinsic properties, or can be generated by external electromagnetic fields or mechanical deformations. Researchers analyze how driven quantum systems can lead to new topological states of matter.
When a topological insulator is “driven” by an applied electromagnetic field, its behavior cannot be predicted based on how it acts when the driving is absent. Theorists show that new conducting edge states can appear and that a new topological invariant, instead of the well-known Chern number, is needed to classify conducting edge states in driven topological insulators.
Quantum annealing is a quantum enhanced heuristic optimization algorithm that exploits quantum tunneling. New work shows that it can significantly outperform its classical analog (simulated annealing) as well as the most popular classical algorithm for simulating quantum annealing (quantum Monte Carlo).
Superconducting qubit experiments cannot be conducted without nonreciprocal devices such as circulators and directional amplifiers. Researchers show that both of these kinds of devices can be realized using a single Josephson circuit.
Communication that relies on quantum carriers, like single photons, can achieve a level of privacy unattainable by classical communication methods. In a new experiment, single microwave photons are used as carriers of quantum information in a manner robust to loss.
A new analysis of quantum error mitigation, which attempts to limit the effects of errors in near-term quantum computers, shows that two proposed techniques can work in small systems without the need for extra qubits or peripheral devices.
A new scheme could offer a technologically viable solution for remedying computational errors in near-term quantum devices.
A new approach for suppressing noise in quantum computation uses multiple copies of a quantum state to cancel out certain kinds of noise, using much less overhead than traditional techniques.
A ten-qubit system based on spins in impure diamond achieves coherence times of over a minute.
A new proposal for how to encode quantum information in the rotational states of individual molecules could protect these qubits from losing information as a result of noise.
Major technical improvements to a quantum computer based on trapped ions could bring a large-scale version closer to reality.
Two-qubit gate errors remain a major bottleneck on the road to robust quantum computing. A new approach to designing a key element of such gates dramatically improves their fidelity.
The demonstration that ions can be precisely manipulated in a trap containing integrated photonics paves the way for a large-scale trapped-ion quantum processor.
A microchannel quantum dot integrated with a superconducting resonator allows for the precision trapping and detection of single electrons on superfluid helium above 1 K, demonstrating control in conditions suited for scalable quantum processors.
A neutral-atom quantum computing system that can repeatedly measure, reuse, and replace ancilla qubits without disrupting others enables longer computations and advances scalable, fault-tolerant operation.
’t Hooft anomalies prevent mixed quantum states from separating into simpler subsystems, revealing a novel phase with robust long-range entanglement. This offers insights into exotic matter and potential quantum technologies.
Analytical and numerical tools adapted from statistical physics reveal phase transitions in quantum control landscapes, explaining when new optimal strategies emerge and guiding the design of more efficient quantum technologies.
