Related Experiment Video
Updated: Jul 16, 2025
12:19
Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source
Published on: April 4, 2017
8.4K
Single-energy-measurement integral fluctuation theorem and nonprojective measurements
Daniel Alonso1, Antonia Ruiz García1
1Departamento de Física and IUdEA, Universidad de La Laguna, 38203 La Laguna, Tenerife, Spain.
Physical Review. E
|September 19, 2023
Summary
This study explores Jarzynski-type equality for work using unsharp measurements, revealing how measurement characteristics and induced noise affect results. The findings highlight deviations from projective measurement cases, especially with non-informative measurements.
Area of Science:
- Quantum thermodynamics
- Statistical mechanics
- Measurement theory
Background:
- Jarzynski equality relates non-equilibrium work to equilibrium free energy.
- Nonprojective unsharp measurements are crucial in quantum systems.
- Understanding work in monitored quantum systems is key.
Purpose of the Study:
- To investigate Jarzynski-type equality under nonprojective unsharp measurements.
- To analyze the influence of measurement characteristics and noise on work relations.
- To explore the role of quantum coherences in these processes.
Main Methods:
- Defining work based on energy measurements and conditioned states.
- Analyzing the Jarzynski equality's dependence on coherences, meter characteristics, and noise.
- Investigating scenarios based on the ratio of energy spectrum distance to meter resolution.
- Quantifying coherences using relative entropy of coherence.
Main Results:
- The Jarzynski equality is modified by coherences, meter properties, and induced noise.
- Noise effects differ from projective measurements, often introducing multiplicative factors.
- Measurement resolution relative to energy spectrum spacing dictates deviations.
- Non-informative measurements can lead to corrections in the work relation.
Conclusions:
- Unsharp measurements introduce complexities to Jarzynski-type equalities.
- The characteristics of the measurement apparatus significantly impact thermodynamic relations.
- Coherences play a vital role in understanding work fluctuations in monitored quantum systems.
Related Concept Videos
02:46Uncertainty in Measurement: Reading Instruments
38.3K
Counting is the type of measurement that is free from uncertainty, provided the number of objects being counted does not change during the process. Such measurements result in exact numbers. By counting the eggs in a carton, for instance, one can determine exactly how many eggs are there in the carton. Similarly, the numbers of defined quantities are also exact. For example, 1 foot is exactly 12 inches, 1 inch is exactly 2.54 centimeters, and 1 gram is exactly 0.001 kilograms. Quantities...
38.3K
04:08The Uncertainty Principle
23.4K
Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that there is a fundamental limit to how accurately one can measure both a particle’s position and its momentum simultaneously. The more accurate the measurement of the momentum of a particle is known, the less accurate the position at that time is known and vice versa. This is what is now called the Heisenberg uncertainty principle. He...
23.4K
03:37Uncertainty in Measurement: Accuracy and Precision
73.9K
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.
73.9K
01:15Parseval's Theorem for Fourier transform
1.1K
Parseval's theorem is a fundamental principle in signal processing that enables the calculation of a signal's energy in either the time domain or the frequency domain. This theorem is pivotal in demonstrating energy conservation between these two domains, ensuring that the computed energy value remains consistent regardless of the domain of analysis.
To understand Parseval's theorem, it is essential to first comprehend how signal energy is typically calculated. When considering a...
To understand Parseval's theorem, it is essential to first comprehend how signal energy is typically calculated. When considering a...
1.1K
01:17Energy and Power Signals
329
In an electrical system with a resistor, voltage and current signals facilitate the measurement of power and energy across the resistor. For a continuous-time signal, the total energy over a time interval is defined as the integral of the square of the signal's magnitude over that interval. Mathematically, this is expressed as:
329
00:59Uncertainty: Overview
595
In analytical chemistry, we often perform repetitive measurements to detect and minimize inaccuracies caused by both determinate and indeterminate errors. Despite the cares we take, the presence of random errors means that repeated measurements almost never have exactly the same magnitude. The collective difference between these measurements - observed values - and the estimated or expected value is called uncertainty. Uncertainty is conventionally written after the estimated or expected value.
595