9 papers · 1 filter
Black Box Work Extraction and Composite Hypothesis Testing
Kaito Watanabe, Ryuji Takagi
Work extraction is one of the most central processes in quantum thermodynamics. However, the prior analysis of optimal extractable work has been restricted to a limited operational…
Universal trade-off structure between symmetry, irreversibility, and quantum coherence in quantum processes
Hiroyasu Tajima, Ryuji Takagi, Yui Kuramochi
Symmetry, irreversibility, and quantum coherence are foundational concepts in physics. Here, we present a universal tradeoff relation between these three concepts. This particularl…
Mixed-state additivity properties of magic monotones based on quantum relative entropies for single-qubit states and beyond
Roberto Rubboli, Ryuji Takagi, Marco Tomamichel
We prove that the stabilizer fidelity is multiplicative for the tensor product of an arbitrary number of single-qubit states. We also show that the relative entropy of magic become…
When quantum memory is useful for dense coding
Ryuji Takagi, Masahito Hayashi
We discuss dense coding with copies of a specific preshared state between the sender and the receiver when the encoding operation is limited to the application of group represe…
Arbitrary Amplification of Quantum Coherence in Asymptotic and Catalytic Transformation
Naoto Shiraishi, Ryuji Takagi
Quantum coherence is one of the fundamental aspects distinguishing classical and quantum theories. Coherence between different energy eigenstates is particularly important, as it s…
Virtual quantum resource distillation
Xiao Yuan, Bartosz Regula, Ryuji Takagi +1
Distillation, or purification, is central to the practical use of quantum resources in noisy settings often encountered in quantum communication and computation. Conventionally, di…