Search FQXi


If you are aware of an interesting new academic paper (that has been published in a peer-reviewed journal or has appeared on the arXiv), a conference talk (at an official professional scientific meeting), an external blog post (by a professional scientist) or a news item (in the mainstream news media), which you think might make an interesting topic for an FQXi blog post, then please contact us at forums@fqxi.org with a link to the original source and a sentence about why you think that the work is worthy of discussion. Please note that we receive many such suggestions and while we endeavour to respond to them, we may not be able to reply to all suggestions.

Please also note that we do not accept unsolicited posts and we cannot review, or open new threads for, unsolicited articles or papers. Requests to review or post such materials will not be answered. If you have your own novel physics theory or model, which you would like to post for further discussion among then FQXi community, then please add them directly to the "Alternative Models of Reality" thread, or to the "Alternative Models of Cosmology" thread. Thank you.

You may also view a list of all blog entries.

 RSS feed | RSS help
RECENT FORUM POSTS

Steve Dufourny: "In your theory wich is an assumption .....and in my theory wich is also an..." in Towards the unification...

Jonathan Dickau: "In my theory... Early universe evolution happens under the octonions and..." in Towards the unification...

John Cox: ""where work is the coherent component of energy radiated by the qubit." ..." in The energetic cost of...

Lorraine Ford: "When are physicists going to stop lying? They CLAIM they believe in..." in Understanding...


RECENT ARTICLES
click titles to read articles

Time to Think
Philosopher Jenann Ismael invokes the thermodynamic arrow of time to explain how human intelligence emerged through culture.

Lockdown Lab Life
Grounded physicists are exploring the use of online and virtual-reality conferencing, and AI-controlled experiments, to maintain social distancing. Post-pandemic, these positive innovations could make science more accessible and environmentally-friendly.

Is Causality Fundamental?
Untangling how the human perception of cause-and-effect might arise from quantum physics, may help us understand the limits and the potential of AI.

Building Agency in the Biology Lab
Physicists are using optogenetics techniques to make a rudimentary agent, from cellular components, which can convert measurements into actions using light.

Think Quantum to Build Better AI
Investigating how quantum memory storage could aid machine learning and how quantum interactions with the environment may have played a role in evolution.


FQXi BLOGS
January 27, 2021

New Blog Entries
Bookmark and Share

The energetic cost of work extraction by Alexia Auffeves
By ZEEYA MERALI • Dec. 19, 2020 @ 18:14 GMT

We analyze work extraction from a qubit into a wave guide (WG) acting as a battery, where work is the coherent component of the energy radiated by the qubit. The process is stimulated by a wave packet whose mean photon number (the battery's charge) can be adjusted. We show that the extracted work is bounded by the qubit's ergotropy, and that the bound is saturated for a large enough battery's charge. If this charge is small, work can still be extracted. Its amount is controlled by the quantum coherence initially injected in the qubit's state, that appears as a key parameter when energetic resources are limited. This new and autonomous scenario for the study of quantum batteries can be implemented with state-of-the-art artificial qubits coupled to WGs.



Ref: Monsel, Fellous Asiani, Huard, Auffèves, PHYSICAL REVIEW LETTERS 124, 130601 (2020)



Keywords: #quarantinethermo
6 comments | view comments


Thermodynamics beyond the weak coupling limit: energy-temperature uncertainty relation by Janet Anders
By ZEEYA MERALI • Dec. 17, 2020 @ 20:13 GMT

A key assumption in the standard thermodynamic description of macroscopic systems is that the system’s interaction with its environment is very weak and can be neglected. For microscopic systems, however, this assumption breaks down. In this talk I will illustrate the impact of strong coupling between a quantum system and its environment in two instances: i) The modification of a harmonic oscillator's thermal energy when strongly coupled to an environment [1], and ii) the combination of thermal uncertainty with quantum uncertainty in a general energy-temperature thermodynamic uncertainty relation [2]. The energy-temperature uncertainty relation is valid for classical and quantum systems at all coupling strengths. But in the

quantum regime, strong coupling can lead to non-commutativity effects that create coherences even in equilibrium, which increase temperature uncertainty as well as modify a system's heat capacity. The strong coupling corrections are described by the average Wigner-Yanase-Dyson skew information, a quantity connected to measures of coherence.



Keywords: #quarantinethermo
5 comments | view comments


Multi time point (thermodynamic) constraints for periodically driven systems by Raam Uzdin
By ZEEYA MERALI • Dec. 17, 2020 @ 19:56 GMT

Standard thermodynamics deals with initial and final states and not much is known on what happens in between. By extending the notion of passivity to periodically driven systems, we obtain constraints on the dynamics under periodic driving.



Keywords: #quarantinethermo
0 comments


Quantum Engine Cools and Heats Simultaneously
By ZEEYA MERALI • Dec. 17, 2020 @ 19:07 GMT

FQXi’s Franco Nori and colleagues at RIKEN in Japan have developed a nanodevice that act as a either a heat engine, or a mini-fridge—or, with an added quantum twist— it can both cool and heat at the same time. Their paper was published a paper in Physical Review Letters in October.

You wouldn’t usually want to combine a fridge and a heater—at least not in a macroscale device. But on the nanoscale, such a device might be useful for quickly switching between the two functions, on a quantum computing chip.

In a normal, macroscale fridge, you exchange heat between two baths of fluid: compressing one bath causes it to heat up, while expanding the other makes it cool. In the nano engine, this process is mimicked by increasing or decreasing the gap between internal energy levels in an electron. The team monitored whether the engine was functioning as a heater or a fridge by monitoring microwaves that were emitted by the device. When it functions as both simultaneously, the emitted microwaves combine to create a characteristic interference pattern.
0 comments


Understanding consciousness within the known laws of physics by Carlo Rovelli
By CARLO ROVELLI • Nov. 16, 2020 @ 07:12 GMT

Abstract: I do not share the feeling that consciousness (whatever this means) cannot be understood in the context of the known physical laws. So far we do not understand it well, but neither do we fully understand thunderstorms, for that matter. I offer three small contributions in the direction of a direct naturalistic account of consciousness: (i) a purely physical account of agency and the openness of the future, which traces the source of information to past low entropy; (ii) a purely physical basis for a simple notion of "meaning"; and (iii) a suggestion that current understanding of quantum matter (without need of panpsychism) weakens the apparent hiatus between the mental and the physical.



Keywords: Mathematical Consciousness Science
122 comments | view comments

Recent Blog Entries

Minimal Phenomenal Experience by Thomas Metzinger
By JOHANNES KLEINER
One classical approach to explaining a complex target phenomenon is to define a minimal model - for example, of conscious experience as such. Is “pure awareness” a form of phenomenal character sui generis, which cannot be reductively defined or...
November 16th, 2020 | -1 comments | view blog entry & comments

Unfolding Argument - Replies, Comments and Panel...
By JOHANNES KLEINER
Quite recently, an argument has been proposed which aims to show that Integrated Information Theory, and in fact all theories that define consciousness in terms of the mutual interaction of a system’s parts, cannot explain consciousness....
November 16th, 2020 | -1 comments | view blog entry & comments

Aikyons, Octonions, and Unification by Tejinder...
By TEJINDER SINGH
This elementary video describes a recently proposed theory of unification, the Aikyon theory. The theory builds on the deep connection between the octonions and the elementary particles.



Keywords: Octonions; Quantum Gravity; ...
October 10th, 2020 | 10 comments | view blog entry & comments

Towards the unification of the four fundamental...
By TEJINDER SINGH
This is a voice narration of a seminar given at the Albert Einstein Institute, Potsdam on September 21, 2020. It describes the new theory of unification reported in arXiv:2009.05574



Keywords: Quantum Foundations; Trace ...
October 10th, 2020 | 206 comments | view blog entry & comments

John Barrow
By DAVID SLOAN
It is with great sadness that we learnt of the death of John Barrow. John was a member of FQXi’s scientific council and contributed in shaping our research direction and focus. John was an accomplished physicist as both researcher and teacher, and...
October 2nd, 2020 | 0 comments | view blog entry & comments

A causal account of spatial experience: IIT and...
By JOHANNES KLEINER
In this talk, Andrew Haun (Assistant Scientist in the Center for Sleep and Consciousness at the University of Wisconsin-Madison) will present an application of the Integrated Information Theory (IIT) of consciousness to the problem of spatial...
August 22nd, 2020 | 6 comments | view blog entry & comments

The empirical quest to understand consciousness...
By JOHANNES KLEINER
In the last decades, studies of consciousness - once considered outside the scope of empirical science - have become part and parcel of cognitive science. To meet the challenge of scientifically operationalizing this high-level phenomenon, different...
August 22nd, 2020 | 237 comments | view blog entry & comments

An Opinionated Introduction to Phenomenology by...
By JOHANNES KLEINER
Phenomenology studies the structure and dynamics of conscious experience. Sincxe its inception in the early 20th century, hundreds of thousands of pages of detailed phenomenological analysis have been produced. In the last few decades this work has...
August 22nd, 2020 | 35 comments | view blog entry & comments

Undecidability, Uncomputability, and...
By DAVID SLOAN
FQXi's essay contests are always set up as a challenge for our community to push back on the boundaries of our understanding. This year was no different, as we asked you to decide how something could be undecidable, compute what we would find...
July 29th, 2020 | 17 comments | view blog entry & comments

Film Screening: "Infinite Potential: The Life and...
By ZEEYA MERALI
[picture]You're invited to a special free film screening and panel discussion event, "Quantum Theories of Consciousness," on July 18th 2020, organized by our friends at The Fetzer Memorial Trust, in partnership with The Center for Consciousness...
July 13th, 2020 | 4 comments | view blog entry & comments

Please enter your e-mail address:
Note: Joining the FQXi mailing list does not give you a login account or constitute membership in the organization.