scholarly journals New Reentrant Insulating Phases in Strongly Interacting 2D Systems with Low Disorder

2018 ◽  
Author(s):  
Richard L.J. Qiu ◽  
Chieh-Wen Liu ◽  
Shuhao Liu ◽  
Xuan P.A. Gao
Keyword(s):  
Magnetic Field ◽  
Oxide Semiconductor ◽  
Future Research ◽  
Metallic State ◽  
Zero Field ◽  
Strongly Correlated ◽  
Strongly Interacting ◽  
Intermediate Phases ◽  
Experimental Findings ◽  
Low Magnetic Field

The apparent metal-insulator transition (MIT) in two-dimension (2D) was discovered by Kravchenko et al. [1] more than two decades ago in strongly interacting 2D electrons residing in a Si-metal-oxide-semiconductor field-effect transistor (Si-MOSFET). Its origin remains unresolved. Recently, low magnetic field reentrant insulating phases (RIPs), which dwell between the zero-field (B=0) metallic state and the integer quantum Hall (QH) states where the Landau-level filling factor υ > 1, have been observed in strongly correlated 2D GaAs hole systems with large interaction parameter rs (~20-40) and high purity. A new complex phase diagram was proposed, which includes zero field MIT, low magnetic field RIPs, integer QH states, fractional QH states, high field RIPs and insulating phases (HFIPs) with υ < 1 in which the insulating phases are explained by the formation of Wigner crystal. Furthermore, evidences of new intermediate phases were reported. All contribute to the further understandings of the puzzle. This review article serves the purpose of summarizing those recent experimental findings and theoretical endeavors, to foster future research efforts.

scholarly journals New Reentrant Insulating Phases in Strongly Interacting 2D Systems with Low Disorder

2018 ◽  
Vol 8 (10) ◽  
pp. 1909 ◽  
Author(s):  
Richard Qiu ◽  
Chieh-Wen Liu ◽  
Shuhao Liu ◽  
Xuan Gao
Keyword(s):  
Magnetic Field ◽  
Oxide Semiconductor ◽  
Future Research ◽  
Metallic State ◽  
Zero Field ◽  
Strongly Correlated ◽  
Strongly Interacting ◽  
Intermediate Phases ◽  
Experimental Findings ◽  
Low Magnetic Field

The metal-insulator transition (MIT) in two-dimension (2D) was discovered by Kravchenko et al. more than two decades ago in strongly interacting 2D electrons residing in a Si-metal-oxide-semiconductor field-effect transistor (Si-MOSFET). Its origin remains unresolved. Recently, low magnetic field reentrant insulating phases (RIPs), which dwell between the zero-field (B = 0) metallic state and the integer quantum Hall (QH) states where the Landau-level filling factor υ > 1, have been observed in strongly correlated 2D GaAs hole systems with a large interaction parameter, rs, (~20–40) and a high purity. A new complex phase diagram was proposed, which includes zero-field MIT, low magnetic field RIPs, integer QH states, fractional QH states, high field RIPs and insulating phases (HFIPs) with υ < 1 in which the insulating phases are explained by the formation of a Wigner crystal. Furthermore, evidence of new intermediate phases was reported. This review article serves the purpose of summarizing those recent experimental findings and theoretical endeavors to foster future research efforts.

Critical current and microstructure of uniaxially aligned, polycrystalline YBa2Cu3O7−δ

1992 ◽  
Vol 7 (6) ◽  
pp. 1317-1327 ◽  
Author(s):  
J.E. Tkaczyk ◽  
C.L. Briant ◽  
J.A. DeLuca ◽  
E.L. Hall ◽  
P.L. Karas ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Critical Current ◽  
High Field ◽  
Zero Field ◽  
Field Region ◽  
Fine Grain ◽  
Axis Alignment ◽  
Low Magnetic Field ◽  
Magnetically Aligned

Three processing routes that generate uniaxial alignment but otherwise yield very different microstructure and critical current are compared. Fine grain size and c-axis alignment are obtained in magnetically aligned ceramics, pyrolyzed thick films, and in situ deposited thin films. The dense, well-aligned microstructure of the in situ process produces the highest zero field critical current Jc > 104 A/cm2 at 77 K. However, the critical current is suppressed in low magnetic field, suggesting that uniaxial alignment is not sufficient to avoid Josephson-type intergranular coupling. Above 1 T, the critical current of the aligned ceramic dominates in spite of its less ideal microstructure. The critical current in this high field region is one to two orders of magnitude greater than that of nonaligned material. This result implies the existence of a 3-d percolative network of strong links.

WEAK FIELD MAGNETIZATION AND SUSCEPTIBILITY FLUCTUATION IN Bi2Sr2CaCu2Oy SINGLE CRYSTALS

1989 ◽  
Vol 03 (14) ◽  
pp. 1045-1051 ◽  
Author(s):  
G. H. CHEN ◽  
G. YANG ◽  
Y. F. YAN ◽  
S. L. JIA ◽  
Y. M. NI ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystals ◽  
Temperature Increase ◽  
Weak Field ◽  
Experimental Measurements ◽  
Zero Field ◽  
Two Dimensional ◽  
Magnetization Curves ◽  
Field Limit ◽  
Low Magnetic Field

Some magnetization curves of single crystal of Bi 2 Sr 2 CaCu 2 O y in low magnetic field H ‖ c axis are given. The magnetization loop is getting smaller with the temperature increase and then disappears at temperature even higher than T c . The experimental measurements of the susceptibility in zero-field limit show that the results can be treated with two-dimensional thermo-fluctuation theory.

scholarly journals Chip-Scale Ultra-Low Field Atomic Magnetometer Based on Coherent Population Trapping

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1517
Author(s):  
Hyun-Gue Hong ◽  
Sang Eon Park ◽  
Sang-Bum Lee ◽  
Myoung-Sun Heo ◽  
Jongcheol Park ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Ground State ◽  
Coherent Population Trapping ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Resonance Signal ◽  
Low Field ◽  
Low Magnetic Field ◽  
Population Trapping ◽  
Wide Operating

We report a chip-scale atomic magnetometer based on coherent population trapping, which can operate near zero magnetic field. By exploiting the asymmetric population among magnetic sublevels in the hyperfine ground state of cesium, we observe that the resonance signal acquires sensitivity to magnetic field in spite of degeneracy. A dispersive signal for magnetic field discrimination is obtained near-zero-field as well as for finite fields (tens of micro-tesla) in a chip-scale device of 0.94 cm3 volume. This shows that it can be readily used in low magnetic field environments, which have been inaccessible so far in miniaturized atomic magnetometers based on coherent population trapping. The measured noise floor of 300 pT/Hz1/2 at the zero-field condition is comparable to that of the conventional finite-field measurement obtained under the same conditions. This work suggests a way to implement integrated atomic magnetometers with a wide operating range.

HYMU 80

Alloy Digest ◽  
1971 ◽  
Vol 20 (10) ◽  
Keyword(s):  
Magnetic Field ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Heat Treating ◽  
Initial Permeability ◽  
Nickel Iron ◽  
Technology Corporation ◽  
Carpenter Technology Corporation ◽  
Low Magnetic Field ◽  
Maximum Permeability

Abstract Carpenter HYMU 80 is an unoriented 80% nickel-iron-molybdenum alloy which offers extremely high initial permeability and maximum permeability with minimum hysteresis loss at low magnetic field strengths. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-5. Producer or source: Carpenter Technology Corporation. Originally published May 1953, revised October 1971.

scholarly journals Ground state and stability of the fractional plateau phase in metallic Shastry–Sutherland system TmB4

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matúš Orendáč ◽  
Slavomír Gabáni ◽  
Pavol Farkašovský ◽  
Emil Gažo ◽  
Jozef Kačmarčík ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Ground State ◽  
Constant Magnetic Field ◽  
Paramagnetic Phase ◽  
The Other ◽  
Zero Field ◽  
Plateau Phase ◽  
Low Field ◽  
Zero Field Cooling

AbstractWe present a study of the ground state and stability of the fractional plateau phase (FPP) with M/Msat = 1/8 in the metallic Shastry–Sutherland system TmB4. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin. In this case the FPP states are closely associated with the half plateau phase (HPP, M/Msat = ½), mediate the HPP to the low-field antiferromagnetic (AF) phase and depend on the thermodynamic history. Thus, in the same place of the phase diagram both, the stable and the metastable (dynamic) fractional plateau (FP) states, can be observed, depending on the way they are reached. In case of metastable FP states thermodynamic paths are identified that lead to very flat fractional plateaus in the FPP. Moreover, with a further decrease of magnetic field also the low-field AF phase becomes influenced and exhibits a plateau of the order of 1/1000 Msat.

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