12 papers · 1 filter
Quantum Incapacity beyond No-Cloning and PPT Mechanisms
Chengkai Zhu, Xin Wang
We show an explicit qutrit channel whose private and quantum capacities both vanish, although it is neither antidegradable nor positive under partial transposition (PPT). This reso…
Witness expansion: A unified framework for analytical and measurable mixed-state resource detection
Yifan Tang, Chengkai Zhu, Yuzhen Zhang +6
Quantum information science aims to harness different kinds of quantum resources to accomplish specific information-processing tasks. These resources also play an increasingly impo…
Invariant Measures and Weak-Magic-Injection Asymptotics in Random Monitored Quantum Circuits
Guocheng Zhen, Xuanrong Yang, Chengkai Zhu +2
Monitored quantum circuits combine scrambling with measurement-conditioned state updates, while non-Clifford perturbations inject magic into otherwise stabilizer-compatible dynamic…
Entanglement cost of bipartite quantum channel discrimination under positive partial transpose operations
Chengkai Zhu, Shuyu He, Gereon KoÃmann +1
Quantum channel discrimination is a fundamental task in quantum information processing. In the one-shot regime, discrimination between two candidate channels is characterized by th…
Optimal Hamiltonian recognition of unknown quantum dynamics
Chengkai Zhu, Shuyu He, Yu-Ao Chen +2
Identifying unknown Hamiltonians from their quantum dynamics is a pivotal challenge in quantum technologies. In this paper, we introduce Hamiltonian recognition, a framework that b…
Virtual Quantum Markov Chains
Yu-Ao Chen, Chengkai Zhu, Keming He +2
Quantum Markov chains generalize classical Markov chains for random variables to the quantum realm and exhibit unique inherent properties, making them an important feature in quant…