FerMix - Fermionic Mixtures of Ultracold Atoms: Pairing, Superfluidity, and Quantum Phases

超冷费米气体是一个新兴的强相互作用量子物质研究领域的核心。现在可以在实验室中创建新的模型系统，并对相关参数进行出色的控制。限制几何形状和费米能量是可以控制的，作为超冷气体的一个独特特征，粒子间相互作用的强度可以在很大范围内进行调节。该研究领域将原子和分子物理学的方法与其他各种学科联系起来，如多体量子物理和凝聚态物理。超冷费米气体领域的一个新进展是将不同的超冷物种结合在一起，从而产生两个不同费米子的量子简并混合物或费米子和玻色子的混合物。这大大拓宽了实验的可能性，并开辟了一系列有趣的研究前景。所涉及的两个不同物种可以相互独立地操纵，这例如允许对禁闭和相关的费米能量进行独立控制。新的费米子配对机制变得容易实现，比如重费米子和轻费米子之间的配对，或者玻色子介导的配对，导致了新的超流体相。对这些多体现象的探索将极大地挑战实验和理论研究，并将推动该领域远远超出目前的知识状态。合作研究项目FerMix将欧洲领先研究人员的紧密联系的个别项目与理论和实验活动相结合，将欧洲对混合超冷费米气体的努力集中在一起。该项目按照四个主要目标组织：(I)制备强相互作用和强关联系统，(Ii)研究新的配对和相互作用现象，(Iii)探索新的超流性区域，以及(Iv)研究光学晶格中的新量子相。

Ultracold Fermi gases are at the heart of an emerging research field on strongly interacting quantum matter. New model systems can now be created in the laboratory with superb control of the relevant parameters. Confinement geometries and Fermi energies can be manipulated and, as a unique feature of ultracold gases, the strength of the interparticle interaction can be tuned over a wide range. The research field connects methods from atomic and molecular physics with various other disciplines, like many-body quantum physics and condensed-matter physics. A new development in the field of ultracold Fermi gases is to combine different ultracold species and thus to create quantum-degenerate mixtures of two different fermions or mixtures of fermions with bosons. This considerably widens the experimental possibilities and opens up a broad range of intriguing research prospects. The two different species involved can be manipulated independently from each other which e.g. allows for an independent control of the confinement and the relevant Fermi energies. New regimes of fermion pairing become accessible, like pairing beween a heavy and a light fermion or boson-mediated pairing, leading to novel superfluid phases. The exploration of these many-body phenomena will greatly challenge both experimental and theoretical research and will promote the field far beyond the present state of knowledge.The collaborative research project FerMix focuses European efforts on mixed ultracold Fermi gases by combining strongly interconnected individual projects of leading European researchers with a balance of theoretical and experimental activities. The project is organized along the four main objectives of (i) the preparation of strongly interacting and strongly correlated systems, (ii) studies of new pairing and interaction phenomena, (iii) the exploration of novel regimes of superfluidity, and (iv) studies on novel quantum phases in optical lattices.