Spin-Polarized Quantum Fluids and Solids

MRS Bulletin ◽  
1993 ◽  
Vol 18 (8) ◽  
pp. 38-43
Author(s):  
Kevin S. Bedell ◽  
Isaac F. Silvera ◽  
Neil S. Sullivan
Keyword(s):  
Magnetic Ordering ◽  
Quantum Fluids ◽  
Einstein Condensation ◽  
Many Body ◽  
Spin Polarized ◽  
Many Body Systems ◽  
The Rich ◽  
Bose Einstein ◽  
Physical Phenomena

The spin-polarized phases of the quantum fluids and solids, liquid 3He, solid 3He, and spin-aligned hydrogen have generated considerable excitement over the past fifteen years. The introduction of high magnetic fields (B ∼ 10–30 T) in conjunction with low temperatures (T ≲ 100 mK) has given rise to opportunities for exploring some of the new phases predicted for these materials. There is a broad range of physical phenomena that can be accessed in this regime of parameter space—unconventional superfluidity, unusual magnetic ordering, Bose-Einstein condensation and Kosterlitz-Thouless transitions, to name a few. This is most surprising since this plethora of complicated states of matter are present in some of the most uncomplicated materials. The rich variety of phases found in these materials are all examples of collective phenomena of quantum many-body systems, and they serve as prototypes for developing an understanding of magnetism and order/disorder processes in other systems, and for the design and characterization of new materials.

NEW FORMS OF QUANTUM MATTER NEAR ABSOLUTE ZERO TEMPERATURE

2007 ◽  
Vol 16 (12b) ◽  
pp. 2413-2419
Author(s):  
WOLFGANG KETTERLE
Keyword(s):  
Atomic Physics ◽  
Cold Atoms ◽  
Einstein Condensation ◽  
Many Body ◽  
New Techniques ◽  
Quantum Reflection ◽  
Fermionic Atoms ◽  
Interacting Systems ◽  
Bose Einstein ◽  
Physical Phenomena

In my talk at the workshop on fundamental physics in space I described the nanokelvin revolution which has taken place in atomic physics. Nanokelvin temperatures have given us access to new physical phenomena including Bose–Einstein condensation, quantum reflection, and fermionic superfluidity in a gas. They also enabled new techniques of preparing and manipulating cold atoms. At low temperatures, only very weak forces are needed to control the motion of atoms. This gave rise to the development of miniaturized setups including atom chips. In Earth-based experiments, gravitational forces are dominant unless they are compensated by optical and magnetic forces. The following text describes the work which I used to illustrate the nanokelvin revolution in atomic physics. Strongest emphasis is given to superfluidity in fermionic atoms. This is a prime example of how ultracold atoms are used to create well-controlled strongly interacting systems and obtain new insight into many-body physics.

Bose–Einstein condensation and heat capacity of spin-polarized atomic hydrogen

2010 ◽  
Vol 405 (9) ◽  
pp. 2171-2174 ◽  
Author(s):  
M.K. Al-Sugheir ◽  
A.S. Sandouqa ◽  
B.R. Joudeh ◽  
S. Al-Omari ◽  
M. Awawdeh ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Atomic Hydrogen ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Spin Polarized ◽  
Bose Einstein

scholarly journals Anharmonicity-induced criticality of collective excitation in a trapped Bose–Einstein condensate

2018 ◽  
Vol 32 (31) ◽  
pp. 1850345
Author(s):  
Qun Wang ◽  
Bo Xiong
Keyword(s):  
Collective Mode ◽  
Collective Excitation ◽  
Einstein Condensate ◽  
Low Energy ◽  
Many Body ◽  
Bose Einstein Condensate ◽  
Large Numbers ◽  
Many Body Systems ◽  
Repulsive Forces ◽  
Bose Einstein

We investigate the low-energy excitations of a dilute atomic Bose gas confined in a anharmonic trap interacting with repulsive forces. The dispersion law of both surface and compression modes is derived and analyzed for large numbers of atoms in the trap, which show two branches of excitation and appear two critical values, where one of them indicates collective excitation which would be unstable dynamically, and the other one indicates the existing collective mode with lower frequency under anharmonic influence than that in harmonic trapping case. Our work reveals the key role played by the anharmonicity and interatomic forces which introduce a rich structure in the dynamic behavior of these new many-body systems.

PHYSICAL CHARACTERIZATION OF PURE AND SUBSTITUTED TETRAGONAL LaBaCaCu3O7-δ SUPERCONDUCTOR

2001 ◽  
Vol 15 (14) ◽  
pp. 415-453 ◽  
Author(s):  
V. P. S. AWANA ◽  
A. V. NARLIKAR
Keyword(s):  
Magnetic Ordering ◽  
Superconducting Properties ◽  
Anionic Sites ◽  
X Ray ◽  
Structural Details ◽  
The Rich ◽  
Reported Data ◽  
Capacity Data ◽  
Structural Aspects

The high T c superconductor, forming the focus of the present review, presents an interesting situation where, despite its oxygen content close to 7.0, the system prefers to crystallize in tetragonal structure, as distinct from exhaustively studied orthorhombic RE:123 ( REBa 2 Cu 3 O 7, RE = rare earth) compounds. Its optimum T c is decided by the cation intermixing at various sites, unlike that in case of normal RE:123, where all cationic sites are fully occupied and fixed, leaving the anionic sites free for oxygen filling. In this, we review the rich crystal chemistry of this compound and discuss it in conjunction with its unusual superconducting properties. The article is divided in five parts: (1) first we discuss variously reported interesting finer structural details and superconductivity of pristine LaBaCaCu 3 O 7-δ (La:1113) superconductor. The La, Ba and Ca sites are found to be intermixed with respect to their nominal sites of the standard RE:123 structure. (2) We examine the structural aspects and superconductivity of La 1-x RE x BaCaCu 3 O 7 (RE = Nd, Dy, Sm and Pr). Unlike RE:123 and 124 compounds, the RE:1113 compounds form only with light rare earths such as La, Pr and Nd. Pr:1113 compound is found to be an insulator with Pr moments ordering magnetically at around 8 K, unlike at 17 K for Pr:123. (3) Studies of Pr substitution reveal that relative T c depression due to Pr in the (La,Nd) 1-x Pr x BaCaCu 3 O 7 system is less in comparison to that found for La or Nd site Pr substituted (La,Nd) 1-x Pr x Ba 2 Cu 3 O 7. (4) The results of superconductivity and structural details are reviewed for LaBaCaCu 3-x M x O 7 (M = Fe, Co, Ni, Ga and Zn) and finally (5) we summarize our conclusions. The results in terms of T c depression due to these impurities in the parent La:1113 system are seen as similar to those observed for RE:124 ( REBa 2 Cu 4 O 8) and Nd:214 ( Nd 2-x Ce x CuO 4), but are different from RE:123 and La:214. The results of structural details, superconductivity and magnetic ordering presented in the four parts for La 1-x RE x BaCaCu 3-y M y O 7 (RE = Nd, Dy, Sm, Pr with 1.0 ≥ x ≥ 0.0, and M = Fe, Co, Ni, Ga and Zn with 0.24 ≥ y ≥ 0.0 were obtained from X-ray and neutron diffraction and using AC and DC magnetic susceptibility, electrical resitivity and heat capacity data as a function of temperature. This review is mainly a consolidated work of the authors, including their collaboration from various laboratories and the reported data of other workers, all being duly acknowledged in the text.

MEMORIAL TRIBUTE TO MANFRED L. RISTIG (1935–2011)

2013 ◽  
Vol 27 (29) ◽  
pp. 1347003
Author(s):  
JOHN W. CLARK
Keyword(s):  
Matrix Theory ◽  
Microscopic Theory ◽  
Quantum Fluids ◽  
Strong Interactions ◽  
Many Body ◽  
Exchange Effects ◽  
Nuclear Systems ◽  
Hypernetted Chain ◽  
Many Body Systems ◽  
Density Matrix Theory

Manfred Ristig was a leading contributor to the advancement of microscopic theory of strongly interacting quantum many-body systems for over four decades. This retrospective on his life and scientific career pays tribute to his pivotal role in the development of correlated wavefunction approaches to quantitative ab initio description of quantum fluids, nuclear systems and condensed matter more generally. Highlights include his contributions to the formulation of Fermi hypernetted chain theory and correlated density matrix theory. Special attention is given to Ristig's seminal work of recent years, which has yielded rich insights into the interplay of exchange effects (arising from quantum statistics) and the strong interactions between constituent bosons or fermions.

ANTHONY LEGGETT: FEENBERG MEDALIST 1999 CONDENSED MATTER AS A TEST-BED FOR FUNDAMENTAL QUANTUM MECHANICS

2001 ◽  
Vol 15 (10n11) ◽  
pp. 1305-1311 ◽  
Author(s):  
C. E. CAMPBELL ◽  
J. W. CLARK ◽  
E. KROTSCHECK ◽  
L. P. PITAEVSKII
Keyword(s):  
Quantum Coherence ◽  
High Temperature Superconductivity ◽  
Einstein Condensation ◽  
Test Bed ◽  
Many Body ◽  
Atomic Systems ◽  
Liquid Theory ◽  
Macroscopic Quantum Coherence ◽  
Key Aspects ◽  
Bose Einstein

The Eugene Feenberg Medal is awarded to Anthony J. Leggett in recognition of his seminal contributions to Many-Body Physics, including the explanation of the remarkable properties of superfluid 3 He in the millikelvin regime, important results in Fermi-liquid theory applied to metals, fundamental new insights into macroscopic quantum coherence, elucidation of key aspects of high-temperature superconductivity, and pioneering studies of the implications of Bose-Einstein condensation in atomic systems.

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