# Reality variation under monitoring with weak measurements

**Authors:** Marcos L. W. Basso, Jonas Maziero  
**arXiv:** [2112.05882](https://arxiv.org/abs/2112.05882)  
**Date:** 2021-12-11  
**Summary page:** https://www.summarizepaper.com/en/paper/2112.05882v2/

## Key points

- Marcos L. W. Basso and Jonas Maziero explore reality variation in quantum systems
- Bilobran and Angelo developed a formal framework for understanding (ir)reality in quantum systems
- Dieguez and Angelo introduced monitoring through weak projective non-revealed measurements to study reality variation for different observables
- Monitoring observable X typically increases its reality, affecting incompatible observables like X'
- Surprising scenarios were observed where the reality of X' exceeded that of X, challenging conventional expectations
- Instances were noted where monitoring X did not impact the established reality of maximally incompatible observable X'
- Investigation into consistency of reality variation across different pairs of observables under monitoring
- The authors devised a quantum circuit to implement the monitoring map experimentally using IBM's quantum computers

## Summary

In their paper titled "Reality Variation Under Monitoring with Weak Measurements," Marcos L. W. Basso and Jonas Maziero delve into the concept of reality variation in quantum systems. They build upon the foundational work of Bilobran and Angelo on (ir)reality characterization and Dieguez and Angelo's exploration of reality variation through monitoring with weak measurements. Inspired by Einstein-Podolsky-Rosen's elements of reality, Bilobran and Angelo developed a formal framework for understanding (ir)reality in quantum systems. This framework defines a measure of (ir)realism or (in)definiteness for observables based on system preparation. Building on this foundation, Dieguez and Angelo introduced the concept of monitoring through weak projective non-revealed measurements to study how reality varies for different observables. They particularly focused on the relationship between an observable X and its incompatible counterpart X'. The authors found that an unrevealed measurement of observable X typically increases its reality, consequently boosting the reality of incompatible observables like X'. However, they also discovered intriguing nuances in this relationship. Surprisingly, they observed scenarios where the variation in the reality of X' exceeded that of X, challenging conventional expectations. Additionally, they noted instances where the monitoring map applied to X did not impact the established reality of X', even when these observables were maximally incompatible. Moreover, Basso and Maziero investigated whether the variation in reality was consistent across different pairs of observables under monitoring. They found cases where both observables experienced identical changes in reality despite being maximally incompatible. To support their theoretical findings, the authors devised a quantum circuit to implement the monitoring map experimentally using IBM's quantum computers. Overall, this study provides valuable insights into how reality evolves within quantum systems under weak measurements and offers new perspectives on the dynamics of (ir)reality relationships between observables in quantum mechanics.