Current Induced G-Factor Shift in Modulation Doped Si Quantum Wells

2006 ◽  
Vol 984 ◽  
Author(s):  
Hans Malissa ◽  
Wolfgang Jantsch ◽  
Friedrich Schäffler ◽  
Zbyslaw Wilamowski
Keyword(s):  
Magnetic Field ◽  
Quantum Wells ◽  
Electric Current ◽  
Magnetic Field Direction ◽  
G Factor ◽  
Conduction Electrons ◽  
Simple Effect ◽  
Spin Resonance ◽  
The Magnetic Field ◽  
A Current

AbstractWe report the observation of a particularly simple effect of spin-orbit coupling which allows for efficient manipulation of spins by an electric current in semiconductor nanostructures. Passing an electric current density of j = 2.5 mA/cm through a modulation doped Si quantum well (density of 5 × 1011 cm-2) perpendicular to an in-plane magnetic field, we observe a shift of the spin resonance of the conduction electrons (CESR) by about 0.1 mT. This shift reverses sign when we invert (i) the current direction, (ii) the magnetic field direction and it vanishes for perpendicular magnetic field. We show that this current-induced shift in g-factor, i.e., its dependence on current and carrier density, its temperature dependence and its anisotropy can be consistently and quantitatively explained in terms of the Bychkov-Rashba coefficient determined earlier from the CESR broadening and the g-factor anisotropy [1]. Other sources of magnetic field (e.g. the Oersted effect) are negligible. This effect can be utilized for g-factor tuning, and thus for local spin manipulation: passing a current through some part of a sample may be utilized to bring those electrons into resonance with a microwave field. These spins are thus excited to Rabi oscillations and, using current pulses of suitable duration, π rotations (or by any other angle) can be achieved.

Construction of a Cost Effective Current Balance for Physics Teaching

2013 ◽  
Vol 770 ◽  
pp. 374-377
Author(s):  
Apichart Sankote ◽  
Kheamrutai Thamaphat ◽  
Supanee Limsuwan
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Magnetic Force ◽  
Magnetic Field Direction ◽  
Horizontal Segment ◽  
Applied Current ◽  
Copper Sheet ◽  
Physics Teaching ◽  
The Magnetic Field ◽  
A Current

In this work, a method to measuring the magnitude of a uniform magnetic field in space using current balance was described. A simple experimental set was designed and constructed using low-cost materials. This constructed current balance consists of copper sheet, weight pan, and acrylic sheet. A copper sheet was cut into a U-shape and attached at the end of acrylic balance arm. A weight pan was hanged in the opposite side of the balance arm with high sensitivity to a small torque. The horizontal segment of the U-shaped copper sheet, which the length l was 3 cm, was located inside the influence of an uniform magnetic field produced by two parallel bar magnets with opposite poles facing each other. The magnetic field direction was perpendicular to the horizontal segment. When a current was supplied to the copper sheet, the magnetic force acting on a horizontal segment of length l carrying a current I in a magnetic field B was given by. In the experiment, the current was varied from 0 1 A. For each value of applied current, the magnetic force on a thin straight sheet of length l was measured by adding masses to the pan until the balance arm moved to the equilibrium between opposing gravitational and magnetic forces. The results showed that the magnetic force increased linearly with increasing applied current. By plotting a linear graph of magnetic force versus applied current, the magnetic field B can be calculated from . The calculated and actual values of B were 100.32 and 100.13 mT, respectively. This constructed current balance is an excellent tool for high school and undergraduate fundamental physics courses. Students will be excited when they see the balance arm rising or going down due to magnitude and direction of current flowing in a conductor wire.

MAGNETORESISTANCE IN COPPER

2008 ◽  
Vol 22 (25n26) ◽  
pp. 4434-4441
Author(s):  
SHIGEJI FUJITA ◽  
NEBI DEMEZ ◽  
JEONG-HYUK KIM ◽  
H. C. HO
Keyword(s):  
Magnetic Field ◽  
Relaxation Time ◽  
Kinetic Theory ◽  
Anisotropic Magnetoresistance ◽  
Magnetic Field Direction ◽  
Conduction Electrons ◽  
Fcc Lattice ◽  
A Charge ◽  
The Magnetic Field ◽  
Cyclotron Mass

The motion of the guiding center of magnetic circulation generates a charge transport. By applying kinetic theory to the guiding center motion, an expression for the magnetoconductivity σ is obtained: σ = e2ncτ/M*, where M* is the magnetotransport mass distinct from the cyclotron mass, nc the density of the conduction electrons, and τ the relaxation time. The density nc depends on the magnetic field direction relative to copper's fcc lattice, when Cu's Fermi surface is nonspherical with “necks”. The anisotropic magnetoresistance is analyzed based on a one-parameter model, and compared with experiments. A good fit is obtained.

VALLEY SPLITTING AND g-FACTOR IN AlAs QUANTUM WELLS

2009 ◽  
Vol 23 (12n13) ◽  
pp. 2948-2954
Author(s):  
C. A. DUARTE ◽  
G. M. GUSEV ◽  
T. E. LAMAS ◽  
A. K. BAKAROV ◽  
J.-C. PORTAL
Keyword(s):  
Magnetic Field ◽  
Quantum Wells ◽  
Quantum Confinement ◽  
Zeeman Splitting ◽  
Exchange Contribution ◽  
G Factor ◽  
Valley Splitting ◽  
Perpendicular Component ◽  
Magneto Resistance ◽  
The Magnetic Field

Here we present the results of magneto resistance measurements in tilted magnetic field and compare them with calculations. The comparison between calculated and measured spectra for the case of perpendicular fields enable us to estimate the dependence of the valley splitting as a function of the magnetic field and the total Landé g -factor (which is assumed to be independent of the magnetic field). Since both the exchange contribution to the Zeeman splitting as well as the valley splitting are properties associated with the 2D quantum confinement, they depend only on the perpendicular component of the magnetic field, while the bare Zeeman splitting depends on the total magnetic field. This information aided by the comparison between experimental and calculated gray scale maps permits to obtain separately the values of the exchange and the bare contribution to the g -factor.

scholarly journals THE MAGNETIC PROPERTIES MEASUREMENT OF COIL FOR GRAVITATIONAL ACCELERATION DETERMINATION

2020 ◽  
Vol 5 (2) ◽  
pp. 119-128
Author(s):  
Cherly Salawane ◽  
Supriyadi Supriyadi ◽  
Ronaldo Talapessy ◽  
Mirtha Yunitha Sari Risakotta
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Field Strength ◽  
Electric Current ◽  
Graphical Method ◽  
Current Strength ◽  
Gravitational Acceleration ◽  
The Earth ◽  
The Magnetic Field ◽  
A Current

The value of the gravitational acceleration of the earth above the earth’s surface depends on the position of the latitude and longitude of the earth’s surface, in other words, because the shape of the earth’s surface is not round like a ball. The magnitude of gravity is not the same everywhere on the surface of the earth. The purpose of this study is to analyze the value of the earth’s gravitational acceleration in a laboratory using a current balance with a graphical method. Fluctuations in the value of the magnetic field strength (B) and the value of the electric current strength (i) on the current balance cause the value of laboratory gravitational acceleration (glab) to vary in the transfer of electric charge (q) according to coil type. The magnitude of the earth’s gravitational acceleration value obtained in a laboratory with a current balance for each type of coil is as follows: SF-37 glab-nr=9.89 m/s2, SF-38 glab-nr=9.90 m/s2, SF-39 glab-nr=9.76 m/s2, SF-40 glab-nr=9.95 m/s2, SF-41 glab-nr=9.75 m/s2 dan SF-42 glab-nr=9.93 m/s2. The results obtained indicate that the value of the earth’s gravitational acceleration in a laboratory close to the literature value is the value of the glab-nr in the SF-37 coil type of 9.89 m/s2.

COMPREHENSIVE STUDY OF SPIN-FLIP EXCITATIONS IN CdZnTe/CdZnMnTe QUANTUM WELLS

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1610-1614
Author(s):  
DAISUKE FUKUOKA ◽  
KOUSHIRO ARAHARA ◽  
TAKAAKI KOYAMA ◽  
NAOKI TANAKA ◽  
KENICHI OTO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
Electron Spin ◽  
Energy Difference ◽  
Magnetic Field Direction ◽  
Kerr Rotation ◽  
Spin Configuration ◽  
Spin Flip ◽  
The Magnetic Field

Spin-flip excitations in non-doped Cd 0.93 Zn 0.07 Te/Cd 0.48 Zn 0.04 Mn 0.48 Te quantum wells have been comprehensively studied by spin-flip Raman scattering (SFRS) spectroscopy and time-resolved Kerr rotation (TRKR) spectroscopy. In 4 nm quantum well, two spin-flip Raman peaks were observed in addition to the multiple Mn 2+ spin-flip scatterings. The spin-flip energies are isotropic against the magnetic field direction and well described by modified Brillouin functions. Based on the circumstantial analysis, they are assigned to the spin-flip of residual electrons and the electron spin-flip in the localized exciton, respectively, even though the large energy difference between the two electron spin-flip processes is a puzzle. While, in 9 nm quantum well a strange spin-flip excitation was observed together with a very weak Mn 2+ spin-flip scattering. The spin-flip energy changed strangely up to the magnetic field 4T, and then linearly increased with field (| g *|=1.15). A high-resolution TRKR spectroscopy revealed an unusual temperature dependence, which resembled "softening mode" of spin resonance observed in p-doped ferromagnetic CdMnTe quantum wells. However, these behaviors are well understood by an "inverted spin configuration", which results from a negative g*-factor and a very weak s-d interaction between the electrons and the manganese ions in the barrier.

Dependence of multipleMn2+spin-flip Raman scattering in quantum wells on the magnetic field direction

2008 ◽  
Vol 77 (11) ◽  
Author(s):  
L. C. Smith ◽  
J. J. Davies ◽  
D. Wolverson ◽  
M. Lentze ◽  
J. Geurts ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Raman Scattering ◽  
Quantum Wells ◽  
Field Direction ◽  
Magnetic Field Direction ◽  
Spin Flip ◽  
The Magnetic Field

Study of MFM Application in Semiconductor Failure Analysis

2004 ◽  
Author(s):  
Way-Jam Chen ◽  
Lily Shiau ◽  
Ming-Ching Huang ◽  
Chia-Hsing Chao
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Current Flow ◽  
Force Microscopy ◽  
The Magnetic Field ◽  
A Current

Abstract In this study we have investigated the magnetic field associated with a current flowing in a circuit using Magnetic Force Microscopy (MFM). The technique is able to identify the magnetic field associated with a current flow and has potential for failure analysis.

A 3 T superconducting magnet for long-run magnetic Compton-scattering experiments

1998 ◽  
Vol 5 (3) ◽  
pp. 937-939 ◽  
Author(s):  
Nobuhiko Sakai ◽  
Hiroshi Ohkubo ◽  
Yasushi Nakamura
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Compton Scattering ◽  
Superconducting Magnet ◽  
Field Direction ◽  
Compton Profile ◽  
Magnetic Field Direction ◽  
Long Run ◽  
Radiation Shields ◽  
The Magnetic Field

A 3 T superconducting magnet has been designed and constructed for magnetic Compton-profile (MCP) measurements with the new capabilities that the magnetic field direction can be altered quickly (within 5 s) and liquid-He refill is not required for more than one week. For the latter capability, two refrigerators have been directly attached to the cryostat to maintain the low temperature of the radiation shields and for the recondensation of liquid He. The system has been satisfactorily operated for over one week.

scholarly journals Enhanced X-ray emission arising from laser-plasma confinement by a strong transverse magnetic field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Evgeny D. Filippov ◽  
Sergey S. Makarov ◽  
Konstantin F. Burdonov ◽  
Weipeng Yao ◽  
Guilhem Revet ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic ◽  
Radiative Properties ◽  
Magnetic Field Direction ◽  
Solid Target ◽  
Total Plasma ◽  
Plasma Confinement ◽  
X Ray ◽  
Magnetic Compression ◽  
The Magnetic Field

AbstractWe analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 10$$^{12}$$ 12 –10$$^{13}$$ 13 W/cm$$^2$$ 2 ) from a solid target as it expands into a homogeneous, strong magnetic field (up to 30 T) that is transverse to its main expansion axis. We find that as early as 2 ns after the start of the expansion, the plasma becomes constrained by the magnetic field. As the magnetic field strength is increased, more plasma is confined close to the target and is heated by magnetic compression. We also observe that after $$\sim 8$$ ∼ 8  ns, the plasma is being overall shaped in a slab, with the plasma being compressed perpendicularly to the magnetic field, and being extended along the magnetic field direction. This dense slab rapidly expands into vacuum; however, it contains only $$\sim 2\%$$ ∼ 2 % of the total plasma. As a result of the higher density and increased heating of the plasma confined against the laser-irradiated solid target, there is a net enhancement of the total X-ray emissivity induced by the magnetization.

scholarly journals The effect of simplifications of a numerical mesh on the results of electromagnetic analysis of the Nuclotron-type cable

2018 ◽  
Vol 177 ◽  
pp. 08004
Author(s):  
Łukasz Tomków
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Current Density ◽  
Electric Current Density ◽  
Electromagnetic Analysis ◽  
First Case ◽  
Single Region ◽  
The Magnetic Field

The model of a single Nuclotron-type cable is presented. The goal of this model is to assess the behaviour of the cable under different loads. Two meshes with different simplifications are applied. In the first case, the superconductor in the cable is modelled as single region. Second mesh considers individual strands of the cable. The significant differences between the distributions of the electric current density obtained with both models are observed. The magnetic field remains roughly similar.

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