Ultrafast all-optical quantum teleportation
Takumi Suzuki, Takaya Hoshi, Akito Kawasaki, Shotaro Oki, Konhi Ichii, Hironari Nagayoshi, Kazuma Takahashi, Takahiro Kashiwazaki
Abstract
Light's intrinsic carrier frequency of hundreds of terahertz theoretically enables information processing at terahertz clock rates. In optical quantum computing, continuous-variable quantum teleportation is the fundamental building block for deterministic logic operations. This protocol transfers unknown quantum states between nodes using quantum entanglement and real-time feedforward of measurement outcomes. However, electrical feedforward bottlenecks currently restrict operational bandwidths to approximately 100 megahertz, preventing the exploitation of light's ultimate speed. Here we show 1-terahertz-bandwidth all-optical quantum teleportation, completely bypassing this electronic limitation. By transferring Bell measurement outcomes optically, we successfully teleported vacuum states across the terahertz band and real-time random coherent wavepackets with a 42-picosecond temporal width. Evaluating the intrinsic state transfer quality, we achieved teleportation fidelities of for the broadband vacuum states and for the dynamic coherent wavepackets. Both results strictly surpass the classical limit of , demonstrating genuine quantum teleportation at ultrafast speeds. Our results establish that optical quantum processing speeds are constrained solely by the nonlinear medium's 1-picosecond-scale response, rather than classical electrical interfaces. This methodology provides a cornerstone for terahertz-clock quantum computers capable of overcoming Moore's law, and paves the way for a high-capacity, telecom-compatible quantum internet.
AI Impact Assessments
(3 models)Scientific Impact Assessment: Ultrafast All-Optical Quantum Teleportation
1. Core Contribution
This paper demonstrates continuous-variable (CV) quantum teleportation with a 1 THz operational bandwidth by replacing the conventional optical-electrical-optical (O-E-O) feedforward pathway with an all-optical feedforward scheme based on phase-sensitive amplification (PSA) in PPLN waveguide optical parametric amplifiers (OPAs). The key innovation is the complete elimination of opto-electronic conversion in the feedforward loop, which has been the primary bandwidth bottleneck since the first demonstration of deterministic CV quantum teleportation in 1998. The concept itself was proposed by Ralph in 1999, making this a quarter-century-delayed experimental realization.
The demonstration includes two complementary measurements: (1) frequency-domain characterization showing 1 THz bandwidth teleportation of vacuum states, and (2) time-domain real-time measurement of teleported random coherent wavepackets with 42 ps temporal modes. Both achieve fidelities (F=0.784 and F=0.770 respectively) exceeding the classical limit of 0.5 and the no-cloning threshold of 2/3.
2. Methodological Rigor
Strengths in experimental design:
Concerns and limitations:
3. Potential Impact
Quantum computing: If CV measurement-based quantum computing matures, this result is foundational. The 10,000× bandwidth improvement over O-E-O methods is transformative for time-domain multiplexed architectures, where clock rate directly determines the number of temporal modes in a fixed-length delay line. The claim of million-mode scalability, while aspirational, becomes geometrically plausible at picosecond wavepacket durations.
Quantum communications: THz-bandwidth teleportation is directly compatible with telecom fiber infrastructure and could enable high-capacity quantum repeaters. The telecom wavelength (1545 nm) operation enhances practical relevance.
Broader impact: The all-optical PSA approach for circumventing electronic bottlenecks has implications beyond quantum teleportation—any CV quantum protocol requiring feedforward (gate teleportation, error correction) benefits from this methodology.
However, several caveats temper the impact:
4. Timeliness & Relevance
This work is highly timely. The Furusawa group has been systematically building toward this demonstration, with recent papers on broadband squeezing generation, picosecond entanglement observation, and all-optical feedforward methodology (refs [23-25]). The convergence of high-quality PPLN waveguide technology with the all-optical processing concept makes this a natural culmination. The work directly addresses the most critical engineering bottleneck in CV optical quantum computing.
5. Strengths & Limitations
Key strengths:
Notable weaknesses:
Overall Assessment
This is a significant experimental achievement that resolves a long-standing bandwidth bottleneck in CV quantum teleportation. The 10,000× bandwidth improvement is genuine and important. However, the paper's claims substantially overreach the demonstrated capabilities, and the path from this proof-of-principle to practical quantum computing remains extremely long. The work is best understood as an important enabling technology demonstration rather than a direct step toward quantum computational advantage.
Generated Apr 17, 2026
Comparison History (186)
Paper 2 likely has higher near-term scientific impact: it demonstrates a concrete experimental breakthrough—1 THz-bandwidth all-optical continuous-variable teleportation—removing a well-known electronic feedforward bottleneck. This is timely, methodologically strong, and broadly relevant to photonic quantum computing, high-speed quantum networks, and ultrafast optics, with clear performance metrics (fidelities above the classical limit) and immediate engineering implications. Paper 1 is conceptually innovative for open-system simulation via partial QEC, but appears more theoretical and may face longer validation and adoption timelines.
Paper 1 demonstrates a fundamental experimental breakthrough—1 THz bandwidth all-optical quantum teleportation—that removes a long-standing electronic bottleneck in quantum information processing. It has immediate implications for quantum computing clock rates, quantum internet infrastructure, and telecom-compatible quantum networks. The achievement of genuine quantum teleportation at ultrafast speeds (picosecond scale) opens entirely new operational regimes. Paper 2 provides important theoretical convergence guarantees for SDP hierarchies in quantum many-body problems, but its impact is more specialized within Hamiltonian complexity theory. Paper 1's experimental nature, broad applicability, and transformative potential give it higher impact.
Paper 1 overcomes a fundamental electronic bottleneck in quantum communication, achieving a 10,000-fold speed increase to the terahertz range. This breakthrough enables ultrafast quantum computing and a high-capacity quantum internet, offering broader and more transformative real-world impact compared to the scalable squeezed light generation presented in Paper 2.
Paper 1 presents a groundbreaking experimental achievement by demonstrating 1-terahertz-bandwidth all-optical quantum teleportation, bypassing long-standing electronic bottlenecks. This fundamental breakthrough enables ultrafast quantum computing and high-capacity quantum internet networks, offering a tangible path to terahertz-clock speeds. While Paper 2 provides a valuable theoretical and architectural advancement for fault-tolerant quantum computation, Paper 1's experimental realization of a paradigm-shifting hardware capability gives it broader and more immediate transformative impact across quantum communication and computing fields.
Paper 1 is more novel and broadly enabling: demonstrating 1‑THz all‑optical feedforward removes a fundamental bandwidth bottleneck in continuous‑variable teleportation, impacting quantum communication and photonic quantum computing architectures at the hardware level. Its methodological advance is clear (terahertz-band real-time teleportation with fidelities above the classical limit) and timely for scalable, telecom-compatible quantum networks. Paper 2 is impactful for quantum chemistry on NISQ via hybrid ML, but its scope is narrower (electronic structure) and depends on model generalization and benchmarking choices, making the foundational impact less universal than Paper 1’s platform-level breakthrough.
Paper 1 demonstrates a groundbreaking experimental achievement—1-THz-bandwidth all-optical quantum teleportation—overcoming a longstanding electronic bottleneck that limited quantum teleportation to ~100 MHz. This represents a ~10,000x improvement in operational bandwidth with immediate implications for quantum computing clock rates and quantum internet infrastructure. The experimental nature, clear fidelity benchmarks exceeding classical limits, and direct path toward terahertz-clock quantum processors give it broader and more immediate impact. Paper 2 provides valuable theoretical bounds for entanglement distribution but addresses a more specialized audience with results that primarily serve as benchmarks rather than enabling new capabilities.
While Paper 1 presents a highly impressive algorithmic advancement for simulating quantum many-body systems, Paper 2 demonstrates a fundamental breakthrough in quantum hardware capabilities. By bypassing the electronic feedforward bottleneck to achieve 1-terahertz-bandwidth all-optical quantum teleportation, Paper 2 unlocks processing speeds 10,000 times faster than current limits. This experimental milestone has profound, cross-disciplinary implications for the realization of ultrafast quantum computers and a high-capacity quantum internet, giving it a broader and more transformative potential real-world impact.
Paper 1 demonstrates a fundamental breakthrough in quantum teleportation by achieving 1 THz bandwidth all-optical operation, bypassing the longstanding electronic feedforward bottleneck. This represents a ~10,000x improvement over prior bandwidths and opens entirely new paradigms for ultrafast quantum computing and quantum internet. The breadth of impact spans quantum computing, telecommunications, and photonics. While Paper 2 makes valuable contributions to quantum error correction architecture, it is more incremental and narrower in scope. Paper 1's experimental demonstration of a long-sought capability has transformative potential across multiple fields.
Paper 1 demonstrates a fundamental breakthrough in quantum information processing by achieving 1-THz-bandwidth all-optical quantum teleportation, overcoming the longstanding electronic feedforward bottleneck. This represents a ~10,000x improvement in operational bandwidth, with broad implications for quantum computing clock rates, quantum internet infrastructure, and telecom compatibility. Its impact spans quantum optics, quantum computing, and communications. Paper 2 makes important but more incremental contributions to quantum error correction via concatenation strategies. While technically sophisticated, its impact is narrower, primarily advancing overhead reduction in fault-tolerant quantum computing architectures.
If verified, Paper 2 would break ML-KEM (CRYSTALS-Kyber), Falcon, Hawk, and NTRU—the core NIST post-quantum cryptography standards—rendering the entire current post-quantum cryptographic infrastructure insecure. This would have immediate, massive consequences for global cybersecurity, standardization efforts, and the foundations of lattice-based cryptography. However, this claim is extraordinary and faces significant skepticism; if correct, its impact dwarfs Paper 1. Paper 1 is impressive experimental work advancing optical quantum computing bandwidth, but its impact is more incremental. The sheer breadth of consequences of Paper 2's claims, if validated, gives it higher potential impact.
Paper 1 is likely higher impact due to its major bandwidth breakthrough (1‑THz all‑optical feedforward) overcoming a well-known electronic bottleneck in continuous-variable teleportation, with clear implications for ultrafast quantum processing and telecom-compatible quantum networking. The novelty is strong (all-optical teleportation at THz rates) and the result is timely for scalable photonic QC. Paper 2 is rigorous and important for waveguide QED many-body physics, but its near-term applications and cross-field breadth are somewhat narrower than a platform-level speedup enabling new regimes of quantum communication/computation.
Paper 1 likely has higher impact due to a striking, timely advance: eliminating the long-standing electronic feedforward bottleneck to achieve 1‑THz-bandwidth continuous-variable quantum teleportation. This is highly novel (all-optical feedforward at ultrafast rates), broadly relevant to quantum networking and photonic/telecom-compatible quantum computing, and could reshape system-level architectures by moving the speed limit to optical nonlinearities. Paper 2 is rigorous and important for bosonic processors, but is more platform-specific (microwave superconducting) and represents an incremental-to-substantial engineering realization of known universality rather than a speed-regime breakthrough.
Paper 2 demonstrates a fundamental experimental breakthrough—achieving 1 THz bandwidth all-optical quantum teleportation, removing the electronic feedforward bottleneck that has limited CV quantum computing for decades. This is a concrete, experimentally validated result with clear fidelities exceeding classical limits, with transformative implications for quantum computing clock rates and quantum internet infrastructure. Paper 1's claim of achieving O(K) measurements via quantum compressed sensing, while interesting, makes extraordinary theoretical claims (eliminating the logarithmic factor) that would require extraordinary validation. Paper 2's impact spans quantum computing, communications, and photonics more immediately and convincingly.
Paper 2 demonstrates a breakthrough in quantum teleportation bandwidth (1 THz), overcoming a fundamental electronic bottleneck that has limited optical quantum computing. This has transformative implications for quantum computing clock rates, quantum internet infrastructure, and telecom compatibility. While Paper 1 achieves impressive ultra-low dissipation in a superconducting oscillator relevant to fundamental physics tests, Paper 2 addresses a broader technological challenge with more immediate and wide-ranging applications across quantum computing, communications, and information processing, likely generating greater cross-disciplinary impact.
Paper 1 likely has higher impact due to a major conceptual/technical advance: eliminating electronic feedforward to achieve 1‑THz-bandwidth continuous-variable teleportation, directly addressing a core bottleneck for ultrafast optical quantum processing. The result is broadly enabling (deterministic gates, high-rate networking) and timely for scalable photonic QC/quantum internet, with strong experimental validation (fidelities well above classical limit). Paper 2 is important as the first TFLN on-chip telecom quantum memory, but its efficiency and storage time remain modest, limiting near-term system-level impact compared to Paper 1’s step-change in operational bandwidth.
Paper 2 likely has higher impact due to a major experimental breakthrough: terahertz-bandwidth, fully all-optical feedforward teleportation that removes a key bottleneck for continuous-variable photonic processing. It is timely and broadly relevant across quantum communication, photonic quantum computing, and ultrafast optics, with clear real-world implications (telecom-compatible quantum networks, high-rate processing). Paper 1 is methodologically strong and valuable for quantum simulation, but is more specialized/theoretical and its near-term impact depends on architectures and implementations, whereas Paper 2 demonstrates a compelling, directly enabling capability.
Paper 2 presents a transformative breakthrough in quantum computing and networking by achieving 1-terahertz-bandwidth all-optical quantum teleportation, bypassing previous 100-MHz electronic bottlenecks. This four-order-of-magnitude improvement in speed directly enables terahertz-clock quantum computers and a high-capacity quantum internet, offering immense real-world applications. While Paper 1 provides valuable corrective insights and optimization for simulating holographic dynamics in SYK models, Paper 2's technological leap in fundamental quantum logic operations demonstrates significantly broader and more immediate impact across the fields of quantum optics, computing, and telecommunications.
Paper 2 demonstrates a major experimental breakthrough—achieving 1 THz bandwidth all-optical quantum teleportation, overcoming a longstanding electronic feedforward bottleneck that limited operations to ~100 MHz. This represents a ~10,000× improvement in operational bandwidth with clear implications for quantum computing, quantum communication, and the quantum internet. The experimental nature, dramatic performance leap, broad applicability across quantum technologies, and direct relevance to scalable quantum information processing give it substantially higher impact potential than Paper 1, which presents a more specialized theoretical contribution to distributed quantum sensing using topological codes.
Paper 2 likely has higher impact due to a more disruptive advance: terahertz-bandwidth, fully all-optical quantum teleportation that removes the longstanding electronic feedforward bottleneck. This is highly novel, timely, and broadly enabling for continuous-variable photonic quantum computing and ultrafast quantum networking, with implications across nonlinear optics, integrated photonics, and information processing. While Paper 1 is a strong, rigorous step toward practical telecom on-chip quantum memory, its >1 µs storage is incremental relative to broader community goals; Paper 2 changes the achievable speed regime and may reshape system architectures.
Paper 1 demonstrates a fundamental breakthrough in quantum information processing by achieving 1-THz-bandwidth all-optical quantum teleportation, bypassing the longstanding electronic feedforward bottleneck. This represents a ~10,000x improvement in operational bandwidth and opens pathways to terahertz-clock quantum computing and high-capacity quantum internet. Its impact spans quantum computing, telecommunications, and fundamental physics. Paper 2, while valuable for quantum computing resource estimation with a clever biplanar architecture, represents an incremental improvement in compilation efficiency for a specific simulation problem, with narrower impact primarily within fault-tolerant quantum computing architecture design.