Quantum Technologies

Quantum technologies harness distinct features of quantum mechanics—most notably superposition, entanglement and coherence—to realise new capabilities in computation, secure communication, sensing and materials science. Quantum processors encode information in quantum bits (qubits) that can exist in coherent superpositions of classical states and become entangled over multiple units, enabling parallelism beyond classical limits. Quantum networks employ single photons or other flying qubits to distribute entanglement over long distances, promising provably secure key distribution and clock synchronisation. Integrated quantum photonic circuits on chip are emerging as scalable platforms for generating, manipulating and detecting quantum states of light. Reservoir-engineering techniques exploit well-designed interactions with tailored environments to prepare, stabilise and protect fragile quantum states without active feedback. Together, these advances point towards fault-tolerant quantum computation, quantum-enhanced sensing at the fundamental limit and a global quantum internet.

Research from Nature Portfolio

Programmable reservoir engineering schemes have extended autonomous stabilisation protocols to prepare continuous manifolds of entangled states. By tailoring always-on dissipative couplings in superconducting qubit arrays, researchers achieved rapid, high-fidelity switching between parity-stabilised Bell states, laying groundwork for measurement-free error-correction primitives. Integrated graph-theoretical quantum photonic processors have been demonstrated on silicon-on-insulator wafers, monolithically embedding thousands of photon-pair sources and reconfigurable waveguide circuits. Such devices generate multipartite, high-dimensional entanglement and sample distributions tied to graph hafnians, marking a step towards programmable quantum simulators and photonic processors. A noiseless room-temperature single-photon isolator based on a chiral atomic vapour V-level scheme has achieved over 30 dB isolation and sub-dB insertion loss without magnetic fields. The direction of isolation is reversed by tuning the optical pump, offering a magnetic-free, quantum-compatible route to protecting delicate quantum states in optical networks.

Research from all publishers

Quantum encryption of arbitrary superposition states has been implemented on superconducting processors using a quantum permutation pad, which generalises classical one-time pads to the quantum domain. By applying random quantum permutation matrices as encryption keys, the scheme securely hides quantum images and superposition wavefunctions, demonstrating a path towards end-to-end secure quantum channels. Optimisation of Shor’s algorithm circuits has yielded minimised controlled-NOT gate counts for attacking elliptic-curve discrete logarithm problems, substantially reducing resource overhead in ion-trap implementations. This analysis refines projections of quantum-computing threats to public-key cryptosystems and informs post-quantum key-size recommendations. A survey of distributed energy resource networks has shown that hybrid deployments combining post-quantum cryptography with quantum key distribution links can defend against emerging quantum attacks. The review identifies practical integration challenges and outlines design principles for resilient, quantum-safe architectures in smart grids and critical infrastructures.

Quantum Technologies publication trend

The graph below shows the total number of articles in quantum technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Qubit: The fundamental unit of quantum information, capable of occupying a coherent superposition of two basis states simultaneously.

Entanglement: A nonclassical correlation between quantum systems in which the state of each subsystem cannot be described independently of the others.

Photonic integrated circuit: A monolithic platform that integrates sources, modulators, interferometers and detectors for manipulating photons on a single chip.

Reservoir engineering: The design of specific system–environment interactions to drive a quantum system autonomously into a target state or manifold.

Quantum permutation pad: A symmetric encryption scheme that applies randomly chosen permutation operators to quantum states, extending one-time-pad security to the quantum realm.

CNOT gate: A two-qubit controlled-NOT quantum logic gate that flips the target qubit only when the control qubit is in the logic 1 state, essential for entanglement generation.

Quantum key distribution (QKD): A method for sharing secret keys using quantum states, whose disturbance upon measurement reveals any eavesdropping.

Post-quantum cryptography (PQC): Classical cryptographic algorithms designed to be resistant to attacks by large-scale quantum computers.

References

1. Engineered dissipation for quantum information science. Nature Reviews Physics (2022).
2. Autonomous stabilization with programmable stabilized state. Nature Communications (2024).
3. Very-large-scale integrated quantum graph photonics. Nature Photonics (2023).
4. Noiseless single-photon isolator at room temperature. Communications Physics (2023).
5. Integrated photonic quantum technologies. Nature Photonics (2019).
6. Quantum encryption of superposition states with quantum permutation pad in IBM quantum computers. EPJ Quantum Technology (2023).
7. Minimizing CNOT-count in quantum circuit of the extended Shor’s algorithm for ECDLP. Cybersecurity (2023).
8. Toward Quantum Secured Distributed Energy Resources: Adoption of Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD). Energies (2022).