Related Experiment Video
Updated: Oct 20, 2025
09:23
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
14.7K
Improved bound on entropy production in a quantum annealer
Michele Campisi1,2, Lorenzo Buffoni2
1NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy.
Physical Review. E
|September 16, 2021
Summary
Average system dissipation is bounded by the asymmetry of its probability distributions. This new lower bound is tighter than existing ones and is experimentally verifiable, demonstrated through quantum annealing.
Area of Science:
- Thermodynamics
- Statistical Mechanics
- Quantum Information
Background:
- The fluctuation theorem provides insights into the statistical properties of thermodynamic processes.
- Existing bounds on dissipation, such as the thermodynamic uncertainty relation, are crucial for understanding energy exchange in systems.
Purpose of the Study:
- To establish a novel lower bound for average dissipation in systems governed by the fluctuation theorem.
- To demonstrate that this bound is tighter and saturable compared to existing relations.
Main Methods:
- Formal mathematical proof using multivariate probability density functions.
- Derivation of a lower bound based on the relative entropy of marginal distributions.
- Experimental application to quantum annealing systems.
Main Results:
- A new lower bound for average dissipation is derived, directly related to the asymmetry of marginal probability distributions.
- The derived bound is proven to be tighter than the thermodynamic uncertainty relation.
- The bound is shown to be saturable, meaning it can be reached under certain conditions.
Conclusions:
- The established lower bound offers a more precise way to quantify dissipation in fluctuating systems.
- The findings have implications for understanding and experimentally estimating dissipation, particularly in quantum systems like quantum annealers.
More Related Videos
Related Concept Videos
02:39Entropy
32.1K
Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...
32.1K
01:20Entropy and the Second Law of Thermodynamics
3.4K
The second law of thermodynamics can be stated quantitatively using the concept of entropy. Entropy is the measure of disorder of the system.
The relation between entropy and disorder can be illustrated with the example of the phase change of ice to water. In ice, the molecules are located at specific sites giving a solid state, whereas, in a liquid form, these molecules are much freer to move. The molecular arrangement has therefore become more randomized. Although the change in average...
The relation between entropy and disorder can be illustrated with the example of the phase change of ice to water. In ice, the molecules are located at specific sites giving a solid state, whereas, in a liquid form, these molecules are much freer to move. The molecular arrangement has therefore become more randomized. Although the change in average...
3.4K
01:10Entropy Change in Reversible Processes
2.8K
In the Carnot engine, which achieves the maximum efficiency between two reservoirs of fixed temperatures, the total change in entropy is zero. The observation can be generalized by considering any reversible cyclic process consisting of many Carnot cycles. Thus, it can be stated that the total entropy change of any ideal reversible cycle is zero.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
2.8K
02:38Third Law of Thermodynamics
20.1K
A pure, perfectly crystalline solid possessing no kinetic energy (that is, at a temperature of absolute zero, 0 K) may be described by a single microstate, as its purity, perfect crystallinity,and complete lack of motion means there is but one possible location for each identical atom or molecule comprising the crystal (W = 1). According to the Boltzmann equation, the entropy of this system is zero.
20.1K
01:14The Second Law of Thermodynamics
6.0K
In the quest to identify a property that may reliably predict the spontaneity of a process, a promising candidate has been identified: entropy. Scientists refer to the measure of randomness or disorder within a system as entropy. High entropy means high disorder and low energy. To better understand entropy, think of a student’s bedroom. If no energy or work were put into it, the room would quickly become messy. It would exist in a very disordered state, one of high entropy. Energy must be...
6.0K
02:05Entropy and Solvation
7.5K
The process of surrounding a solute with solvent is called solvation. It involves evenly distributing the solute within the solvent. The rule of thumb for determining a solvent for a given compound is that like dissolves like. A good solvent has molecular characteristics similar to those of the compound to be dissolved. For example, polar solutions dissolve polar solutes, and apolar solvents dissolve apolar solutes. A polar solvent is a solvent that has a high dielectric constant (ϵ...
7.5K