The fourth fundamental circuit element: principle and applications

Author(s):  
Young Sun

Abstract The relationships between four basic circuit variables - voltage (v), current (i), charge (q), and magnetic flux (ϕ) - have defined three fundamental circuit elements: resistor, capacitor, and inductor. From a symmetry view, there is a fourth fundamental circuit element defined from the relationship between charge and magnetic flux. Historically, a device called memristor was considered to be the fourth element, but it has caused intense controversy because the memristor is conceived based on a nonlinear i-v relationship rather than a direct q-ϕ relationship. Alternatively, a direct correlation between trapped charge (q) and magnetic flux (ϕ) can be built up by employing the magnetoelectric (ME) effects, i.e., magnetic field control of electric polarization and electric field control of magnetization. In this review, we summarize recent progress on the principle and applications of the fourth circuit element based on the ME effects. Both the fourth linear element and nonlinear memelement, termed transtor and memtranstor, respectively, have been proposed and experimentally demonstrated. A complete relational diagram of fundamental circuit elements has been constructed. The transtor with a linear ME effect can be used in a variety of applications such as the energy harvester, tunable inductor, magnetic sensor, gyrator, and transformer etc. The memtranstor showing a pinched hysteresis loop has a great potential in developing low-power nonvolatile electronic devices. The principle is to utilize the states of the ME coefficient αE=dE/dH, instead of resistance, magnetization or electric polarization to store information. Both nonvolatile memories and logic functions can be implemented using the memtranstors, which provides a candidate route toward the logic-in-memory computing system. In addition, artificial synaptic devices that are able to mimic synaptic behaviors have also been realized using the memtranstor. The fourth circuit element and memelement based on the ME effects provide extra degrees of freedom to broaden circuit functionalities and develop advanced electronic devices.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Randy Lemons ◽  
Wei Liu ◽  
Josef C. Frisch ◽  
Alan Fry ◽  
Joseph Robinson ◽  
...  

AbstractThe structural versatility of light underpins an outstanding collection of optical phenomena where both geometrical and topological states of light can dictate how matter will respond or display. Light possesses multiple degrees of freedom such as amplitude, and linear, spin angular, and orbital angular momenta, but the ability to adaptively engineer the spatio-temporal distribution of all these characteristics is primarily curtailed by technologies used to impose any desired structure to light. We demonstrate a laser architecture based on coherent beam combination offering integrated spatio-temporal field control and programmability, thereby presenting unique opportunities for generating light by design to exploit its topology.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Xudong Shen ◽  
Long Zhou ◽  
Yisheng Chai ◽  
Yan Wu ◽  
Zhehong Liu ◽  
...  

Abstract All the magnetoelectric properties of scheelite-type DyCrO4 are characterized by temperature- and field-dependent magnetization, specific heat, permittivity, electric polarization, and neutron diffraction measurements. Upon application of a magnetic field within ±3 T, the nonpolar collinear antiferromagnetic structure leads to a large linear magnetoelectric effect with a considerable coupling coefficient. An applied electric field can induce the converse linear magnetoelectric effect, realizing magnetic field control of ferroelectricity and electric field control of magnetism. Furthermore, a higher magnetic field (>3 T) can cause a metamagnetic transition from the initially collinear antiferromagnetic structure to a canted structure, generating a large ferromagnetic magnetization up to 7.0 μB f.u.−1. Moreover, the new spin structure can break the space inversion symmetry, yielding ferroelectric polarization, which leads to coupling of ferromagnetism and ferroelectricity with a large ferromagnetic component.


2014 ◽  
Vol 70 (a1) ◽  
pp. C178-C178
Author(s):  
Carola Müller ◽  
Sven Lidin

Sometimes, model building in crystallography is like resolving a puzzle: All obvious symmetrical or methodological errors are excluded, you apparently understand the measured patterns in 3D, but the structure solution and/or refinement is just not working. One such nerve-stretching problem arises from metrically commensurate structures (MCS). This expression means that the observed values of the components of the modulation wave vectors are rational by chance and not because of a lock-in. Hence, it is not a superstructure - although the boundaries between the two descriptions are blurry. Using a superstructure model for a MCS decreases the degrees of freedom, and forces the atomic arrangement to an artificial state of ordering. Just imagine it as looking at a freeze frame from a movie instead of watching the whole film. The consequences in structure solution and refinement of MCS are not always as dramatically as stated in the beginning. On the contrary, treating a superstructure like a MCS might be a worthwhile idea. Converting from a superstructure model to a superspace model may lead to a substantial decrease in the number of parameters needed to model the structure. Further, it can permit for the refinement of parameters that the paucity of data does not allow in a conventional description. However, it is well known that families of superstructures can be described elegantly by the use of superspace models that collectively treat a whole range of structures, commensurate and incommensurate. Nevertheless, practical complications in the refinement are not uncommon. Instances are overlapping satellites from different orders and parameter correlations. Notably, MCS occur in intermetallic compounds that are important for the performance of next-generation electronic devices. Based on examples of their (pseudo)hexagonal 3+1D and 3+2D structures, we will discuss the detection and occurrence of MCS as well as the benefits and limitations of implementing them artificially.


Author(s):  
Thomas Prevenslik

Today, the transient Fourier heat conduction equation is not considered valid for the derivation of temperatures from the dissipation of Joule heat in nanoelectronics because the dimension of the circuit element is comparable to the mean free path of phonon energy carriers. Instead, the Boltzmann transport equation (BTE) for ballistic transport based on the scattering of phonons within the element is thought to govern heat transfer. However, phonons respond at acoustic frequencies in times on the order of 10–100 ps, and therefore the BTE would not have meaning if the Joule heat is conserved by a faster mechanism. Unlike phonons with response times limited by acoustic frequencies, heat transfer in nanoelectronics based on QED induced heat transfer conserves Joule heat in times < 1 fs by the creation of EM radiation at optical frequencies. QED stands for quantum electrodynamics. In effect, QED heat transfer negates thermal conduction in nanoelectronics because Joule heat is conserved well before phonons respond. QED induced heat transfer finds basis in Planck’s QM given by the Einstein-Hopf relation in terms of temperature and EM confinement of the atom as a harmonic oscillator. QM stands for quantum mechanics and EM for electromagnetic. Like the Fourier equation, the BTE is based on classical physics allowing the atom in nanoelectronic circuit elements to have finite heat capacity, thereby conserving Joule heat by an increase in temperature. QM differs by requiring the heat capacity of the atom to vanish. Conservation of Joule heat therefore proceeds by QED inducing the creation of excitons (hole and electron pairs) inside the circuit element by the frequency up-conversion of Joule heat to the element’s TIR confinement frequency. TIR stands for total internal reflection. Under the electric field across the element, the excitons separate to produce a positive space charge of holes that reduce the electrical resistance or upon recombination are lost by the emission of EM radiation to the surroundings. TIR confinement of EM radiation is the natural consequence of the high surface to volume ratio of the nanoelectronic circuit elements that concentrates Joule heat almost entirely in their surface, the surfaces coinciding with the TIR mode shape of the QED radiation. TIR confinement is not permanent, present only during the absorption of Joule heat. Charge creation aside, QM requires nanoelectronics circuit elements to remain at ambient temperature while dissipating Joule heat by QED radiation to the surroundings. Hot spots do not occur provided the RI of the circuit element is greater than the substrate or surroundings. RI stands for refractive index. In this paper, QED radiation is illustrated with memristors, PC-RAM devices, and 1/ f noise in nanowires, the latter of interest as the advantage of QM in avoiding hot spots in nanoelectronics may be offset by the noise from the holes created in the circuit elements by QED induced radiation.


Science ◽  
2008 ◽  
Vol 319 (5870) ◽  
pp. 1643-1646 ◽  
Author(s):  
S. Ishiwata ◽  
Y. Taguchi ◽  
H. Murakawa ◽  
Y. Onose ◽  
Y. Tokura

2019 ◽  
Vol 4 (9) ◽  
Author(s):  
Stephan Krohns ◽  
Peter Lunkenheimer

Abstract Multiferroic materials, showing ordering of both electrical and magnetic degrees of freedom, are promising candidates enabling the design of novel electronic devices. Various mechanisms ranging from geometrically or spin-driven improper ferroelectricity via lone-pairs, charge-order or -transfer support multiferroicity in single-phase or composite compounds. The search for materials showing these effects constitutes one of the most important research fields in solid-state physics during the last years, but scientific interest even traces back to the middle of the past century. Especially, a potentially strong coupling between spin and electric dipoles captured the interest to control via an electric field the magnetization or via a magnetic field the electric polarization. This would imply a promising route for novel electronics. Here, we provide a review about the dielectric and ferroelectric properties of various multiferroic systems ranging from type I multiferroics, in which magnetic and ferroelectric order develop almost independently of each other, to type II multiferroics, which exhibit strong coupling of magnetic and ferroelectric ordering. We thoroughly discuss the dielectric signatures of the ferroelectric polarization for BiFeO3, Fe3O4, DyMnO3 and an organic charge-transfer salt as well as show electric-field poling studies for the hexagonal manganites and a spin-spiral system LiCuVO4.


2014 ◽  
Vol 23 (02) ◽  
pp. 1450016
Author(s):  
JIANLI CHEN ◽  
WENXING ZHU

The very large-scale integrated circuit (VLSI) placement problem is to determine the exact location of each movable circuit element within a given region. It is a crucial process in physical design, since it affects performance, power consumption, routability, and heat distribution of a design. In this paper, we propose a VLSI placement flow to handle the large-scale mixed-size placement problem. The main idea of our placement flow is using a floorplanning algorithm to guide the placement of circuit elements. It consists of four steps: (1) With the multilevel framework, circuit elements are clustered into blocks by recursively partitioning; (2) a floorplanning algorithm is performed on every level of the blocks; (3) the macro cells are shifted by a macro shifting technique to determine their exact locations; (4) with each macro cell location fixed, a standard cell placement algorithm is applied to place the remaining objects. The proposed approach is tested on the IBM mixed-size benchmarks and the modern mixed-size (MMS) placement benchmarks. Experimental results show that our approach outperforms the state-of-the-art placers on the solution quality for most of the benchmarks.


2005 ◽  
Vol 128 (3) ◽  
pp. 670-674 ◽  
Author(s):  
Javier Moreno-Valenzuela ◽  
Rafael Kelly

The velocity field control of robot manipulators is addressed in this paper. The proposed algorithm has a hierarchical structure based on a velocity field kinematic control scheme for joint velocity resolution and an inner loop of joint velocity control that uses an observer for friction compensation. Experiments on a two degrees-of-freedom direct-drive arm illustrate the performance of the proposed controller.


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