Operational Definition of the Temperature of a Quantum State

Lipka-Bartosik, Patryk; Perarnau-Llobet, Martí; Brunner, Nicolás

doi:10.1103/physrevlett.130.040401

Cited by 17 publications

(7 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ability to cool also plays a role in a resource theory of passivity [57]: a passive state that is virtually cooler than another one (see [87][88][89] for the notion of virtual temperatures) implies that the former can cool a qubit better than the latter. As explored in [90], notions of cooling and heating can even be used to assign (two) temperatures to non-equilibrium states.…”

Section: Discussionmentioning

confidence: 99%

“…Another convenient property of a resource theory is convexity since it allows us to use many mathematical tools and methods from convex analysis [30]. Indeed, the closed thermal operations are convex, see [20, For the task of cooling and heating that we consider in this work, we are specifically interested in quasi-classical target states, for which the following holds (see also [13, theorem 6] and [90]).…”

Section: The Athermality State (ρmentioning

confidence: 99%

See 1 more Smart Citation

Thermodynamic state convertibility is determined by qubit cooling and heating

Theurer,

Zanoni,

Maria Scandolo

et al. 2023

New J. Phys.

View full text Add to dashboard Cite

Thermodynamics plays an important role both in the foundations of physics and in technological applications. An operational perspective adopted in recent years is to formulate it as a quantum resource theory. At the core of this theory is the interconversion between athermality states, i.e., states out of thermal equilibrium. Here, we solve the question of how athermality can be used to heat and cool other quantum systems that are initially at thermal equilibrium. We then show that the convertibility between quasi-classical resources (resources that do not exhibit coherence between different energy eigenstates) is fully characterized by their ability to cool and heat qubits, i.e., by two of the most fundamental thermodynamical tasks on the simplest quantum systems.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: The Athermality State (ρmentioning

confidence: 99%

Thermodynamic state convertibility is determined by qubit cooling and heating

Theurer,

Zanoni,

Maria Scandolo

et al. 2023

New J. Phys.

View full text Add to dashboard Cite

show abstract

“…There, in the most constrained form, one calls a state transition ρ → ω strictly catalytic if there exists an ancilla in state ω C as well as an "allowed" operation Φ on the new overall system such that Φ(ρ ⊗ ω C ) = ω ⊗ ω C (although there are also "weaker" versions of catalytic transformations; cf. the review article [39]). For thermal operations in the quasi-classical realm, strict catalysis reduces to state transfers x ⊗ z ≺ d y ⊗ z.…”

Section: Cyclic State Transfers and Subspaces In Equilibriummentioning

confidence: 99%

The Thermomajorization Polytope and Its Degeneracies

vom Ende,

Malvetti

2024

Entropy

View full text Add to dashboard Cite

Drawing inspiration from transportation theory, in this work, we introduce the notions of “well-structured” and “stable” Gibbs states and we investigate their implications for quantum thermodynamics and its resource theory approach via thermal operations. It is found that, in the quasi-classical realm, global cyclic state transfers are impossible if and only if the Gibbs state is stable. Moreover, using a geometric approach by studying the so-called thermomajorization polytope, we prove that any subspace in equilibrium can be brought out of equilibrium via thermal operations. Interestingly, the case of some subsystem being in equilibrium can be witnessed via the degenerate extreme points of the thermomajorization polytope, assuming that the Gibbs state of the system is well structured. These physical considerations are complemented by simple new constructions for the polytope’s extreme points, as well as for an important class of extremal Gibbs-stochastic matrices.

show abstract

“…Additionally, the model requires a fully quantum circuit with feedback. 13 The current idea is to employ reinforcement learning to achieve the computation objective. 14…”

Section: ■ Introductionmentioning

confidence: 99%

Quantum Molecular Devices

Kosloff

2024

ACS Phys. Chem Au

View full text Add to dashboard Cite

Miniaturization has been the driving force in contemporary technologies. However, two main obstacles limit further progress: additional reduction in size has reached its quantum limit, and lithography has reached its threshold. Future progress requires tackling three challenges: chemical synthesis of a complete device, active cooling for exploiting quantum characteristics, and quantum coherent control for operation. Chemical synthesis replaces the current top-bottom approach to manufacturing with bottom-up synthesis from elementary building blocks. New ultracold synthetic methods should be developed. An additional challenge is the active cooling of molecules, where the bottleneck is entropy removal. Notably, the current solution, namely, diffusion, is too slow. A coherent approach offers a possible solution; specifically, quantum coherent control is the method of choice for manipulating ultracold matter. Finally, the many degrees of freedom of molecules should be an asset that allows the design and implementation of complex tasks such as sensing communication and computing.

show abstract

Operational Definition of the Temperature of a Quantum State

Cited by 17 publications

References 77 publications

Thermodynamic state convertibility is determined by qubit cooling and heating

Thermodynamic state convertibility is determined by qubit cooling and heating

The Thermomajorization Polytope and Its Degeneracies

Quantum Molecular Devices

Contact Info

Product

Resources

About