Related Experiment Video
Updated: Jun 29, 2026
06:42
Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
No cloning of quantum ensembles
Zhenyu Du1, Siyuan Cheng1, Qi Zhao2
1Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China.
Nature Communications
|June 27, 2026
Summary
Scientists investigated quantum ensemble cloning, finding a new no-cloning theorem. While some barriers can be bypassed for physical systems, characterization remains computationally intractable, impacting quantum information science.
Area of Science:
- Quantum Physics
- Quantum Information Theory
- Quantum Thermodynamics
Background:
- Modern quantum physics allows control of individual quantum systems.
- Characterizing these systems requires measuring nonlinear properties, akin to cloning quantum ensembles.
- Novel non-equilibrium phenomena like deep thermalization and measurement-induced entanglement are being uncovered.
Purpose of the Study:
- To investigate the fundamental laws governing the cloning of quantum ensembles.
- To establish a general no-cloning theorem for arbitrary ensembles.
- To explore whether computational intractability can be circumvented for physical ensembles.
Main Methods:
- Information-theoretic analysis to establish a general no-cloning theorem.
- Investigation of physical ensembles generated by finite-time evolutions.
- Computational complexity analysis even with full circuit knowledge.
Main Results:
- A general no-cloning theorem for arbitrary quantum ensembles was established.
- The cloning barrier can be circumvented for physical ensembles from finite-time evolutions.
- Characterizing these ensembles remains computationally intractable, irrespective of known preparation circuits.
Conclusions:
- New fundamental principles of quantum mechanics are established.
- Intrinsic trade-offs exist between sample complexity, computational complexity, and quantum measurements.
- Problem-specific strategies are necessary for probing measurement-induced quantum phenomena.
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