191 citations · 1.6k across the 34 of their papers we have counts for
34 papers
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…
Virtual quantum resource distillation: General framework and applications
Ryuji Takagi, Xiao Yuan, Bartosz Regula +1
We develop the general framework of virtual resource distillation -- an alternative distillation strategy proposed in [Phys. Rev. Lett. 132, 050203 (2024)], which extends conventio…
Robustness- and weight-based resource measures without convexity restriction: Multicopy witness and operational advantage in static and dynamical quantum resource theories
Kohdai Kuroiwa, Ryuji Takagi, Gerardo Adesso +1
Quantum resource theories (QRTs) provide a unified framework to analyze quantum properties as resources for achieving advantages in quantum information processing. The generalized…
Every quantum helps: Operational advantage of quantum resources beyond convexity
Kohdai Kuroiwa, Ryuji Takagi, Gerardo Adesso +1
Identifying what quantum-mechanical properties are useful to untap a superior performance in quantum technologies is a pivotal question. Quantum resource theories provide a unified…
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…
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…
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…
Universal Sampling Lower Bounds for Quantum Error Mitigation
Ryuji Takagi, Hiroyasu Tajima, Mile Gu
Numerous quantum error-mitigation protocols have been proposed, motivated by the critical need to suppress noise effects on intermediate-scale quantum devices. Yet, their general p…
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…
One-Shot Yield-Cost Relations in General Quantum Resource Theories
Ryuji Takagi, Bartosz Regula, Mark M. Wilde
Although it is well known that the amount of resources that can be asymptotically distilled from a quantum state or channel does not exceed the resource cost needed to produce it,…
Fundamental limits of quantum error mitigation
Ryuji Takagi, Suguru Endo, Shintaro Minagawa +1
The inevitable accumulation of errors in near-future quantum devices represents a key obstacle in delivering practical quantum advantages, motivating the development of various qua…
Correlation in Catalysts Enables Arbitrary Manipulation of Quantum Coherence
Ryuji Takagi, Naoto Shiraishi
Quantum resource manipulation may include an ancillary state called a catalyst, which aids the transformation while restoring its original form at the end, and characterizing the e…
Enhancing quantum models of stochastic processes with error mitigation
Matthew Ho, Ryuji Takagi, Mile Gu
Error mitigation has been one of the recently sought after methods to reduce the effects of noise when computation is performed on a noisy near-term quantum computer. Interest in s…
Operational applications of the diamond norm and related measures in quantifying the non-physicality of quantum maps
Bartosz Regula, Ryuji Takagi, Mile Gu
Although quantum channels underlie the dynamics of quantum states, maps which are not physical channels -- that is, not completely positive -- can often be encountered in settings…
One-Shot Manipulation of Dynamical Quantum Resources
Bartosz Regula, Ryuji Takagi
We develop a unified framework to characterize one-shot transformations of dynamical quantum resources in terms of resource quantifiers, establishing universal conditions for exact…
Fundamental limitations on distillation of quantum channel resources
Bartosz Regula, Ryuji Takagi
Quantum channels underlie the dynamics of quantum systems, but in many practical settings it is the channels themselves that require processing. We establish universal limitations…
Framework for resource quantification in infinite-dimensional general probabilistic theories
Ludovico Lami, Bartosz Regula, Ryuji Takagi +1
Resource theories provide a general framework for the characterization of properties of physical systems in quantum mechanics and beyond. Here, we introduce methods for the quantif…
Operational quantification of continuous-variable quantum resources
Bartosz Regula, Ludovico Lami, Giovanni Ferrari +1
The diverse range of resources which underlie the utility of quantum states in practical tasks motivates the development of universally applicable methods to measure and compare re…
Optimal resource cost for error mitigation
Ryuji Takagi
One of the central problems for near-term quantum devices is to understand their ultimate potential and limitations. We address this problem in terms of quantum error mitigation by…
Application of the Resource Theory of Channels to Communication Scenarios
Ryuji Takagi, Kun Wang, Masahito Hayashi
We introduce a resource theory of channels relevant to communication via quantum channels, in which the set of constant channels --- useless channels for communication tasks --- is…
Benchmarking one-shot distillation in general quantum resource theories
Bartosz Regula, Kaifeng Bu, Ryuji Takagi +1
We study the one-shot distillation of general quantum resources, providing a unified quantitative description of the maximal fidelity achievable in this task, and revealing similar…
Universal limitations on implementing resourceful unitary evolutions
Ryuji Takagi, Hiroyasu Tajima
We derive a trade-off relation between the accuracy of implementing a desired unitary evolution using a restricted set of free unitaries and the size of the assisting system, in te…
Assisted concentration of Gaussian resources
Ludovico Lami, Ryuji Takagi, Gerardo Adesso
In spite of their outstanding experimental relevance, Gaussian operations in continuous-variable quantum systems are subjected to fundamental limitations, as it is known that gener…