1. proposed character set · proposed character set 2. discussion 3. complete outline of cc license...

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Dicke Quantum Spin and Photon Glass in Optical Cavities: Non-equilibrium theory and experimental signatures Michael Buchhold, 1 Philipp Strack, 2 Subir Sachdev, 2 and Sebastian Diehl 1, 3 1 Institut f¨ ur Theoretische Physik, Leopold-Franzens Universit¨ at Innsbruck, A-6020 Innsbruck, Austria 2 Department of Physics, Harvard University, Cambridge MA 02138 3 Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria In the context of ultracold atoms in multimode optical cavities, the appearance of a quantum-critical glass phase of atomic spins has been predicted recently. Due to the long-range nature of the cavity-mediated interac- tions, but also the presence of a driving laser and dissipative processes such as cavity photon loss, the quantum optical realization of glassy physics has no analog in condensed matter, and could evolve into a “cavity glass microscope” for frustrated quantum systems out-of-equilibrium. Here we develop the non-equilibrium theory of the multimode Dicke model with quenched disorder and Markovian dissipation. Using a unified Keldysh path integral approach, we show that the defining features of a low temperature glass, representing a critical phase of matter with algebraically decaying temporal correlation functions, are seen to be robust against the presence of dissipation due to cavity loss. The universality class however is modified due to the Markovian bath. The presence of strong disorder leads to an enhanced equilibration of atomic and photonic degrees of freedom, in- cluding the emergence of a common low-frequency eective temperature. The imprint of the atomic spin glass physics onto a “photon glass” makes it possible to detect the glass state by standard experimental techniques of quantum optics. We provide an unambiguous characterization of the superradiant and glassy phases in terms of fluorescence spectroscopy, homodyne detection, and the temporal photon correlation function g (2) (). PACS numbers: 37.30+i, 42.50.-p, 05.30.Rt, 75.10.Nr I. INTRODUCTION An emerging theme in the research on strongly correlated ultracold atoms is the creation of quantum soft matter phases ranging from nematics and smectics [1, 2], liquid crystals [3], granular materials [4–6], friction phenomena in nonlin- ear lattices [7, 8], to glasses [9–13]. Realizing glasses with strongly interacting light-matter systems bears the promise to study some of the most celebrated achievements in statistical mechanics from a new vantage point. The Parisi solution of mean-field spin glasses [14], for example, continues to trig- ger research more than three decades after its discovery in the early 1980’s, and may have implications for information stor- age [15] and “frustrated” optimization algorithms [16]. The latter is related to the inability of a glass to find its ground state; a feature that makes it inherently non-equilibrium. Historically, quantum eects in soft matter and glasses have not played a prominent role because most soft materials are too large, too heavy and/or too hot and therefore way out- side the quantum regime. Spin and charge glass features have however been invoked in some electronic quantum materials [14, 17], mainly due to RKKY-type interactions or randomly distributed impurities providing a random potential for the electrons. However, here the glassy mechanisms occur of- ten in combination with other more dominant (Coulomb) in- teractions, and it is hard to pin down which eects are truly due to glassiness. Note that the somewhat simpler Bose glass of the Bose Hubbard model [18] (see [19] for a possible re- alization in optical cavities), while in the quantum regime, occurs because of a short-range random potential, and does not generically exhibit some of the hallmark phenomena of frustrated glasses, such as many metastable states, aging, or replica-symmetry breaking. It would clearly be desirable to have a tunable realization of genuinely frustrated (quantum) glasses in the laboratory. Recent work on ultracold atoms in optical cavities [9–11, 19] suggests that it may be possible to create spin- and charge glasses in these systems, which arise because of frustrated couplings of the atomic “qubits” to the dynamical potential of multiple cavity modes. It is appealing to these systems that the photons escaping the cavity can be used for in-situ detection of the atom dynamics (“cavity glass microscope”), and that the interaction mediated by cavity photons is long- ranged. The latter makes the theoretical glass models more tractable and should allow for a realistic comparison of exper- iment and theory. The phases of matter achievable with cavity quantum electrodynamics (QED) systems settle into non-equilibrium steady states typically balancing a laser drive with dissipation channels such as cavity photon loss and atomic spontaneous emission. The notion of temperature is, a priori, not well de- fined. A line of recent research on the self-organization tran- sition of bosonic atoms in a single-mode optical cavity (ex- perimentally realized with a thermal gas of Cesium [20] and with a Bose-Einstein condensate of Rubidium [21, 22]), has established the basic properties of the non-equilibrium phase transition into the self-organized, superradiant phase [23–32]. In particular it was shown that, upon approximating the atom dynamics by a single collective spin of length N/2 and taking the atom number N large, the dynamics can be described by classical equations of motion [25, 29], and that the phase tran- sition becomes thermal due to the drive and dissipation [30]. In this paper, we underpin our previous proposal [10], and show that quenched disorder from multiple cavity modes, leads to qualitatively dierent non-equilibrium steady states with quantum glassy properties. We develop a comprehen- sive non-equilibrium theory for many-body multimode cav- ity QED with quenched disorder and Markovian dissipation. arXiv:1304.5196v1 [cond-mat.quant-gas] 18 Apr 2013

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Page 1: 1. Proposed Character Set · Proposed Character Set 2. Discussion 3. Complete outline of CC license symbols 4. References 5. ... (for details see [5]). Tables such as [6] show the

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Doc Type: Working Group Document Title: Proposal to add CC license symbols to UCS Source: Creative Commons Corporation For consideration by UTC Date: 2018-02-28 Replaces: L2/17-242R (which replaced L2/17-242, which replaced L2/16-283) In this document:

1. Proposed Character Set 2. Discussion 3. Complete outline of CC license symbols 4. References 5. Examples and Figures

1. Proposed Character Set

1. U+2B74 CIRCLED COUNTERCLOCKWISE ARROW

2. U+2B75 CIRCLED DOLLAR SIGN WITH OVERLAID BACKSLASH

3. ! U+1F10D CIRCLED ZERO WITH SLASH

4. ! U+1F16D CIRCLED CC

5. ! U+1F16E CIRCLED C WITH OVERLAID BACKSLASH

6. ! U+1F16F CIRCLED HUMAN FIGURE For the formerly proposed CIRCLED EQUALS SIGN (below), the committee recommends users employ U+229C CIRCLED EQUALS. From L2/17-242R:

CIRCLED EQUALS SIGN (U+2B75)

2. Discussion The set of six CC license symbols are in use to describe a variety of functions, permissions, and concepts related to intellectual property.

rick
Text Box
L2/17-242R2
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Since their introduction in 2002, the CC license symbols have achieved ubiquitous use across web platforms, creation tools, and search engines. The symbols are used to describe at least 1.2 billion works across more than 9 million websites in over 85 countries (for details on the growth and ubiquity of use, see [1] and [2]).

The initial set of CC license symbols (CIRCLED CC, CIRCLED COUNTERCLOCKWISE ARROW, CIRCLED DOLLAR SIGN WITH OVERLAID BACKSLASH) was introduced in 2002. The CIRCLED HUMAN FIGURE, as proposed here, was introduced in 2006. The CIRCLED ZERO WITH OVERLAID BACKSLASH was introduced in 2009, and the CIRCLED C WITH OVERLAID BACKSLASH was introduced in 2010. (For details on history and origin of symbols see [3] and [4].)

The Creative Commons symbol (CIRCLED CC) was designed to work as efficiently on the printed page as on a web page, video credit crawl, or signage. It was designed to be evoked with a keyboard [e.g. (CC)], and to be easy to draw and re-create free-hand. Its design is inspired by the © symbol. Like the © symbol, its primary design is exactly specified (c letterform in a circle), while in current text forms may be used resembling the font design. Similarly, the other symbols in the set (CIRCLED HUMAN FIGURE, CIRCLED COUNTERCLOCKWISE ARROW, CIRCLED DOLLAR SIGN WITH OVERLAID BACKSLASH, CIRCLED ZERO WITH OVERLAID BACKSLASH, CIRCLED C WITH OVERLAID BACKSLASH) were designed to be efficiently evoked as part of the same system (some graphic form within a circle). Their primary designs are exactly specified, while in current text forms may be used resembling the font design. The designs in current text forms is shown in figs. 1-4. Adding these symbols to UCS would enable text interchange in a variety of platforms, as demonstrated in figs. 5-7. In these examples, you see some variation in size, font, and placement, which is common for © symbol as well. The universality of the symbols was confirmed to us by their acquisition into the Modern Museum of Art’s (MoMA) permanent collection, featured alongside symbols already in UCS: the @ symbol and the International Symbol for Recycling (♲) (for details see [5]). Tables such as [6] show the CC license symbols being the only IP symbols in use which have dedicated signs that cannot be represented in UCS.

3. Complete outline of CC license symbols

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Name Character(s) Annex L Name Additional explanation

Creative Commons

CIRCLED CC (U+1F16D)

This symbol is used to indicate a license is a Creative Commons license. It is also used to indicate the reservation of some copyrights. It is also used more broadly to indicate the concept of a commons of creative works.

Attribution

CIRCLED HUMAN FIGURE (U+1F16F)

This symbol is used to specify the attribution condition of a CC license. It is also used to indicate the specific CC Attribution (CC BY) license. It is also used more broadly to indicate the concept of attribution, or credit.

ShareAlike

CIRCLED COUNTERCLOCKWISE ARROW (U+2B74)

This symbol is used to specify the ShareAlike condition of a CC license. It is also used in combination with other symbols to indicate one of the ShareAlike CC licenses. It is also used more broadly to represent the concept of share alike in the non-software creative community (requiring any derivative work to be shared under the same terms).

Noncommercial

CIRCLED DOLLAR SIGN WITH OVERLAID BACKSLASH (U+2B75)

This symbol is used to indicate the NonCommercial condition of a CC license. It is also used in combination with other symbols to indicate one of the NonCommercial CC licenses. It is also used more broadly to represent the concept that no commercial use may be made of a work without permission.

CC0 (read “zero”)

CIRCLED ZERO WITH SLASH (U+1F10D)

This symbol is used to specify the CC0 public domain dedication. It is also used to indicate the proactive surrender of copyright before the term of copyright expires, or “no rights reserved.”

Public Domain

CIRCLED C WITH OVERLAID BACKSLASH (U+1F16E)

This symbol is used to specify the CC Public Domain Mark. It is also used to indicate the public domain status, or absence of copyright, on a work worldwide. It is also used more broadly to represent the concept that a

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work is in the worldwide public domain and free to use without any constraints related to copyright.

4. References

[1] 2016 State of the Commons report

The 2016 State of the Commons report demonstrates the growth of the commons over time and the use of the CC license symbols to tag and describe works in the commons. The full report is available at https://stateof.creativecommons.org/2016/.

[2] Fonts incorporating CC license symbols

Here we present examples of user-developed fonts that incorporate the CC license symbols for use within various communities. This font developed by user Ricardo Barros provides scalable vector for CC license symbols that can be customized for size and color via CSS: http://cc-icons.github.io/. The project itself is licensed under a CC BY license with source code licensed under the MIT license.

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This font package by user Michael Ummels provides the means to typeset CC license symbols within the standard academic typesetting system: https://www.ctan.org/tex-archive/fonts/ccicons. It is a good demonstration of the use and application of CC license symbols within that community. The CC symbol has also been incorporated into Font Awesome, a project that provides useful icons for use in websites: http://fontawesome.io/icon/creative-commons/. This project demonstrates wider demand for the use and application of CC license symbols around the web. The Font Awesome project itself is openly licensed, with documentation under the CC BY license. In addition, Creative Commons developed a font for use by its community which is available at http://mirrors.creativecommons.org/presskit/cc-icons.ttf.

[3] Timeline of introductions of the CC licenses: https://creativecommons.org/about/history/

[4] Origin of the design of CC license symbols: https://medium.com/@creativecommons/a-masterwork-in-simplicity-the-story-of-the-cc-logo-7e2e231a26e7

[5] MoMA’s acquisition of the CC license symbols into its permanent collection

In March 2015, the Modern Museum of Art (MoMA) in New York acquired the CC license symbols into its permanent collection, and debuted the acquisition in an exhibit entitled, “This Is for Everyone: Design Experiments for the Common Good.” The symbols were featured alongside symbols already in UCS, such as the @ symbol and the International Symbol for Recycling (♲). MoMA cited Tim Berners-Lee for the title and intent behind the exhibit: “The exhibition takes its title from British computer scientist Tim Berners-Lee, inventor of the World Wide Web, who lit up the stadium at the 2012 London Summer Olympics opening ceremony with a simple tweet: “This Is for Everyone.” His buoyant message highlighted how the Internet—perhaps the most radical social design experiment of the last quarter century—has created seemingly limitless possibilities for discovering, sharing, and expanding knowledge and information.” In addition to recognizing the universality and utility of the CC symbols, the MoMA acquisition further recognized the symbols’ role in representing the sharing culture of the Internet, and the potential of that culture that is yet to come. Relevant articles announcing and referencing the acquisition:

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● Creative Commons announcement of MoMA’s acquisition of the CC logo and license

icons: https://creativecommons.org/2015/03/04/creative-commons-logo-acquired-by-moma-and-featured-in-new-exhibit/

● MoMA’s announcement of its acquisition of the CC logo and license icons: http://www.moma.org/explore/inside_out/2015/03/04/is-this-for-everyone-new-design-acquisitions-at-moma

● MoMA’s exhibit featuring acquired CC logo and icons: http://www.moma.org/calendar/exhibitions/1501?locale=en

● WIRED’s coverage of the MoMA acquisition: https://www.wired.com/2015/02/inspiring-objects-designed-everyone-arduino-soy-sauce-bottle/

[6] From https://en.wikipedia.org/wiki/Copyright_symbol:

5. Examples and Figures

Fig. 1: The CC license symbols rendered in text, resembling Times New Roman font

(HUMAN FIGURE and COUNTERCLOCKWISE ARROW are not existing characters in UCS so could not be rendered in Times New Roman for this example.) Fig. 2: The CC license symbols rendered in text, resembling Comic Sans font

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(HUMAN FIGURE and COUNTERCLOCKWISE ARROW are not existing characters in UCS so could not be rendered in Comic Sans for this example.) Fig. 3: Flickr’s rendering of CC license symbols Flickr has slightly modified the design of the CC license symbols to fit with its platform aesthetics.

Fig. 4: Zoom-in on Flickr’s rendering of CC license symbols on a photo page

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Fig. 5: Example email referencing CC licenses without CC license symbols in text

Fig. 6: Example email referencing CC licenses with CC license symbols rendered in text (font would be same as Gmail’s default sans serif, which is either Arial or Helvetica)

Rendered versions grossly enlarged for demonstration, but would be similar to size as the © symbol.

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Fig. 7: Example use in print: Tales from the Public Domain: Bound by Law?

The comic book, Tales from the Public Domain: Bound by Law?, employs the CC license symbols to indicate that the work is governed by a CC BY-NC-SA license. (Comic is available at https://web.law.duke.edu/cspd/comics/.) Were the CC license symbols in UCS, the publisher could have rendered the symbols in the same font as the publication for consistency, in this case Comic Sans as demonstrated in fig. 2.

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ISO/IEC JTC 1/SC 2/WG 2 PROPOSAL SUMMARY FORM TO ACCOMPANY SUBMISSIONS

FOR ADDITIONS TO THE REPERTOIRE OF ISO/IEC 10646TP

1PT

Please fill all the sections A, B and C below. Please read Principles and Procedures Document (P & P) from HTUhttp://std.dkuug.dk/JTC1/SC2/WG2/docs/principles.html UTH for

guidelines and details before filling this form. Please ensure you are using the latest Form from HTUhttp://std.dkuug.dk/JTC1/SC2/WG2/docs/summaryform.htmlUTH.

See also HTUhttp://std.dkuug.dk/JTC1/SC2/WG2/docs/roadmaps.html UTH for latest Roadmaps. A. Administrative 1. Title: A proposal to encode Creative Commons license and public domain icons in

UCS

2. Requester's name: Creative Commons Corporation 3. Requester type (Member body/Liaison/Individual contribution): 4. Submission date: 2018-02-28 5. Requester's reference (if applicable): 6. Choose one of the following: This is a complete proposal: X (or) More information will be provided later: B. Technical – General 1. Choose one of the following: a. This proposal is for a new script (set of characters): Proposed name of script: b. The proposal is for addition of character(s) to an existing block: X Name of the existing block: 2. Number of characters in proposal: 6 3. Proposed category (select one from below - see section 2.2 of P&P document): A-Contemporary X B.1-Specialized (small collection) B.2-Specialized (large collection) C-Major extinct D-Attested extinct E-Minor extinct F-Archaic Hieroglyphic or Ideographic G-Obscure or questionable usage symbols 4. Is a repertoire including character names provided? Yes a. If YES, are the names in accordance with the “character naming guidelines” in Annex L of P&P document? Yes b. Are the character shapes attached in a legible form suitable for review? Yes 5. Fonts related: a. Who will provide the appropriate computerized font to the Project Editor of 10646 for publishing the

standard?

Creative Commons Corporation b. Identify the party granting a license for use of the font by the editors (include address, e-mail, ftp-site, etc.): Creative Commons Corporation, PO Box 1866, Mountain View, CA 94042, USA. [email protected]

https://github.com/cc-icons/cc-icons/zipball/master

6. References: a. Are references (to other character sets, dictionaries, descriptive texts etc.) provided? Yes b. Are published examples of use (such as samples from newspapers, magazines, or other sources) of proposed characters attached? Yes 7. Special encoding issues: Does the proposal address other aspects of character data processing (if applicable) such as input, presentation, sorting, searching, indexing, transliteration etc. (if yes please enclose information)? Yes See text 8. Additional Information: Submitters are invited to provide any additional information about Properties of the proposed Character(s) or Script that will assist in correct understanding of and correct linguistic processing of the proposed character(s) or script. Examples of such properties are: Casing information, Numeric information, Currency information, Display behaviour information such as line breaks, widths etc., Combining behaviour, Spacing behaviour, Directional behaviour, Default Collation behaviour, relevance in Mark Up contexts, Compatibility equivalence and other Unicode normalization related information. See the Unicode standard at HTUhttp://www.unicode.orgUTH for such information on other scripts. Also see Unicode Character Database ( Hhttp://www.unicode.org/reports/tr44/ ) and associated Unicode Technical Reports

TP

1PT Form number: N4502-F (Original 1994-10-14; Revised 1995-01, 1995-04, 1996-04, 1996-08, 1999-03, 2001-05, 2001-09, 2003-

11, 2005-01, 2005-09, 2005-10, 2007-03, 2008-05, 2009-11, 2011-03, 2012-01)

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C. Technical - Justification 1. Has this proposal for addition of character(s) been submitted before? Yes If YES explain This version replaces L2/17-242R, which replaced L2/17-242, which replaced L2/16-283 2. Has contact been made to members of the user community (for example: National Body, user groups of the script or characters, other experts, etc.)? No If YES, with whom? If YES, available relevant documents: 3. Information on the user community for the proposed characters (for example: size, demographics, information technology use, or publishing use) is included? Yes Reference: See text 4. The context of use for the proposed characters (type of use; common or rare) Common Reference: See text 5. Are the proposed characters in current use by the user community? Yes If YES, where? Reference: See text 6. After giving due considerations to the principles in the P&P document must the proposed characters be entirely in the BMP? Yes If YES, is a rationale provided? Yes If YES, reference: See text 7. Should the proposed characters be kept together in a contiguous range (rather than being scattered)? Yes 8. Can any of the proposed characters be considered a presentation form of an existing character or character sequence? No If YES, is a rationale for its inclusion provided? If YES, reference: 9. Can any of the proposed characters be encoded using a composed character sequence of either existing characters or other proposed characters? No If YES, is a rationale for its inclusion provided? If YES, reference: 10. Can any of the proposed character(s) be considered to be similar (in appearance or function) to, or could be confused with, an existing character? No If YES, is a rationale for its inclusion provided? If YES, reference: 11. Does the proposal include use of combining characters and/or use of composite sequences? No If YES, is a rationale for such use provided? If YES, reference: Is a list of composite sequences and their corresponding glyph images (graphic symbols) provided? If YES, reference: 12. Does the proposal contain characters with any special properties such as control function or similar semantics? No If YES, describe in detail (include attachment if necessary) 13. Does the proposal contain any Ideographic compatibility characters? No If YES, are the equivalent corresponding unified ideographic characters identified? If YES, reference: