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Convective Dynamics and the Response of Precipitation Extremes to Warming in Radiative-Convective Equilibrium 期刊论文
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2020, 77 (5) : 1637-1660
作者:  Abbott, Tristan H.;  Cronin, Timothy W.;  Beucler, Tom
收藏  |  浏览/下载:20/0  |  提交时间:2020/07/02
Tropics  Extreme events  Precipitation  Radiative-convective equilibrium  Climate change  Cloud resolving models  
Exploring dynamical phase transitions with cold atoms in an optical cavity 期刊论文
NATURE, 2020, 580 (7805) : 602-+
作者:  Halbach, Rebecca;  Miesen, Pascal;  Joosten, Joep;  Taskopru, Ezgi;  Rondeel, Inge;  Pennings, Bas;  Vogels, Chantal B. F.;  Merkling, Sarah H.;  Koenraadt, Constantianus J.;  Lambrechts, Louis;  van Rij, Ronald P.
收藏  |  浏览/下载:23/0  |  提交时间:2020/07/03

Interactions between light and an ensemble of strontium atoms in an optical cavity can serve as a testbed for studying dynamical phase transitions, which are currently not well understood.


Interactions between atoms and light in optical cavities provide a means of investigating collective (many-body) quantum physics in controlled environments. Such ensembles of atoms in cavities have been proposed for studying collective quantum spin models, where the atomic internal levels mimic a spin degree of freedom and interact through long-range interactions tunable by changing the cavity parameters(1-4). Non-classical steady-state phases arising from the interplay between atom-light interactions and dissipation of light from the cavity have previously been investigated(5-11). These systems also offer the opportunity to study dynamical phases of matter that are precluded from existence at equilibrium but can be stabilized by driving a system out of equilibrium(12-16), as demonstrated by recent experiments(17-22). These phases can also display universal behaviours akin to standard equilibrium phase transitions(8,23,24). Here, we use an ensemble of about a million strontium-88 atoms in an optical cavity to simulate a collective Lipkin-Meshkov-Glick model(25,26), an iconic model in quantum magnetism, and report the observation of distinct dynamical phases of matter in this system. Our system allows us to probe the dependence of dynamical phase transitions on system size, initial state and other parameters. These observations can be linked to similar dynamical phases in related systems, including the Josephson effect in superfluid helium(27), or coupled atomic(28) and solid-state polariton(29) condensates. The system itself offers potential for generation of metrologically useful entangled states in optical transitions, which could permit quantum enhancement in state-of-the-art atomic clocks(30,31).


  
Signatures of self-organized criticality in an ultracold atomic gas 期刊论文
NATURE, 2020, 577 (7791) : 481-+
作者:  MacPherson, Laura;  Anokye, Juliana;  Yeung, Miriam M.;  Lam, Enid Y. N.;  Chan, Yih-Chih;  Weng, Chen-Fang;  Yeh, Paul;  Knezevic, Kathy;  Butler, Miriam S.;  Hoegl, Annabelle;  Chan, Kah-Lok;  Burr, Marian L.;  Gearing, Linden J.;  Willson, Tracy;  Liu, Joy;  Choi, Jarny;  Yang, Yuqing;  Bilardi, Rebecca A.;  Falk, Hendrik;  Nghi Nguyen;  Stupple, Paul A.;  Peat, Thomas S.;  Zhang, Ming;  De Silva, Melanie;  Carrasco-Pozo, Catalina;  Avery, Vicky M.;  Khoo, Sim;  Dolezal, Olan;  Dennis, Matthew L.;  Nuttall, Stewart;  Surjadi, Regina;  Newman, Janet;  Ren, Bin;  Leaver, David J.;  Sun, Yuxin;  Baell, Jonathan B.;  Dovey, Oliver;  Vassiliou, George S.;  Grebien, Florian;  Dawson, Sarah-Jane;  Street, Ian P.;  Monahan, Brendon J.;  Burns, Christopher J.;  Choudhary, Chunaram;  Blewitt, Marnie E.;  Voss, Anne K.;  Thomas, Tim;  Dawson, Mark A.
收藏  |  浏览/下载:56/0  |  提交时间:2020/07/03

Self-organized criticality is an elegant explanation of how complex structures emerge and persist throughout nature(1), and why such structures often exhibit similar scale-invariant properties(2-9). Although self-organized criticality is sometimes captured by simple models that feature a critical point as an attractor for the dynamics(10-15), the connection to real-world systems is exceptionally hard to test quantitatively(16-21). Here we observe three key signatures of self-organized criticality in the dynamics of a driven-dissipative gas of ultracold potassium atoms: self-organization to a stationary state that is largely independent of the initial conditions  scale-invariance of the final density characterized by a unique scaling function  and large fluctuations of the number of excited atoms (avalanches) obeying a characteristic power-law distribution. This work establishes a well-controlled platform for investigating self-organization phenomena and non-equilibrium criticality, with experimental access to the underlying microscopic details of the system.


A driven-dissipative gas of ultracold potassium atoms is used to demonstrate three key signatures of self-organized criticality, and provides a system in which the phenomenon can be experimentally tested.


  
Cross-product manipulation with intertemporal constraints: An equilibrium model 期刊论文
ENERGY POLICY, 2019, 134
作者:  Guo, Nongchao;  Lo Prete, Chiara
收藏  |  浏览/下载:10/0  |  提交时间:2020/02/17
Virtual transactions  Financial transmission rights  Electricity price manipulation  Equilibrium models  Mathematical program with equilibrium constraints (MPEC)  
Leveraging plant hydraulics to yield predictive and dynamic plant leaf allocation in vegetation models with climate change 期刊论文
GLOBAL CHANGE BIOLOGY, 2019
作者:  Trugman, Anna T.;  Anderegg, Leander D. L.;  Sperry, John S.;  Wang, Yujie;  Venturas, Martin;  Anderegg, William R. L.
收藏  |  浏览/下载:24/0  |  提交时间:2019/11/27
allocation  ecohydrological equilibrium  leaf area  optimization  plant hydraulics  vegetation models  vegetation water demand  
A 1D RCE Study of Factors Affecting the Tropical Tropopause Layer and Surface Climate 期刊论文
JOURNAL OF CLIMATE, 2019, 32 (20) : 6769-6782
作者:  Dacie, Sally;  Kluft, Lukas;  Schmidt, Hauke;  Stevens, Bjorn;  Buehler, Stefan A.;  Nowack, Peer J.;  Dietmueller, Simone;  Abraham, N. Luke;  Birner, Thomas
收藏  |  浏览/下载:23/0  |  提交时间:2019/11/27
Radiative-convective equilibrium  Tropopause  Climate sensitivity  Ozone  Single column models  
Is improving Nile water quality 'fruitful'? 期刊论文
ECOLOGICAL ECONOMICS, 2019, 161: 20-31
作者:  Osman, Rehab;  Ferrari, Emanuele;  McDonald, Scott
收藏  |  浏览/下载:19/0  |  提交时间:2019/11/27
Water pollution  Irrigation efficiency  Agricultural productivity  Egypt  Computable General Equilibrium (CGE) models  
Identifying the Sources of Convective Memory in Cloud-Resolving Simulations 期刊论文
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2019, 76 (3) : 947-962
作者:  Colin, Maxime;  Sherwood, Steven;  Geoffroy, Olivier;  Bony, Sandrine;  Fuchs, David
收藏  |  浏览/下载:16/0  |  提交时间:2019/04/09
Tropics  Deep convection  Radiative-convective equilibrium  Mesoscale systems  Cloud resolving models  Convective parameterization  
The realized warming fraction: a multi-model sensitivity study 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2018, 13 (12)
作者:  Pfister, Patrik L.;  Stocker, Thomas F.
收藏  |  浏览/下载:13/0  |  提交时间:2019/04/09
climate models  ensemble simulations  realized warming fraction  equilibrium climate sensitivity  physical equilibration  energy balance  ocean heat uptake  
The Influence of Meridional Gradients in Insolation and Longwave Optical Depth on the Climate of a Gray Radiation GCM 期刊论文
JOURNAL OF CLIMATE, 2018, 31 (19) : 7803-7822
作者:  Lutsko, Nicholas J.;  Popp, Max
收藏  |  浏览/下载:15/0  |  提交时间:2019/04/09
Radiative-convective equilibrium  Climatology  Planetary atmospheres  Radiative forcing  Surface temperature  Climate models