scholarly journals Voltage control of magnetism in multiferroic heterostructures

Author(s):  
Ming Liu ◽  
Nian X. Sun

Electrical tuning of magnetism is of great fundamental and technical importance for fast, compact and ultra-low power electronic devices. Multiferroics, simultaneously exhibiting ferroelectricity and ferromagnetism, have attracted much interest owing to the capability of controlling magnetism by an electric field through magnetoelectric (ME) coupling. In particular, strong strain-mediated ME interaction observed in layered multiferroic heterostructures makes it practically possible for realizing electrically reconfigurable microwave devices, ultra-low power electronics and magnetoelectric random access memories (MERAMs). In this review, we demonstrate this remarkable E-field manipulation of magnetism in various multiferroic composite systems, aiming at the creation of novel compact, lightweight, energy-efficient and tunable electronic and microwave devices. First of all, tunable microwave devices are demonstrated based on ferrite/ferroelectric and magnetic-metal/ferroelectric composites, showing giant ferromagnetic resonance (FMR) tunability with narrow FMR linewidth. Then, E-field manipulation of magnetoresistance in multiferroic anisotropic magnetoresistance and giant magnetoresistance devices for achieving low-power electronic devices is discussed. Finally, E-field control of exchange-bias and deterministic magnetization switching is demonstrated in exchange-coupled antiferromagnetic/ferromagnetic/ferroelectric multiferroic hetero-structures at room temperature, indicating an important step towards MERAMs. In addition, recent progress in electrically non-volatile tuning of magnetic states is also presented. These tunable multiferroic heterostructures and devices provide great opportunities for next-generation reconfigurable radio frequency/microwave communication systems and radars, spintronics, sensors and memories.

2016 ◽  
Vol 4 (5) ◽  
pp. 203-204
Author(s):  
Paul R. Berger ◽  
Albert Chin ◽  
Akira Nishiyama ◽  
Meikei Ieong

2020 ◽  
Vol 1 (5) ◽  
Author(s):  
Yasuhiro Takahashi ◽  
Hiroki Koyasu ◽  
S. Dinesh Kumar ◽  
Himanshu Thapliyal

Abstract Silicon Physical Unclonable Function (PUF) is a general hardware security primitive for security vulnerabilities. Recently, Quasi-adiabatic logic based physical unclonable function (QUALPUF) has ultra low-power dissipation; hence it is suitable to implement in low-power portable electronic devices such radio frequency identification (RFID) and wireless sensor networks (WSN), etc. In this paper, we present a design of 4-bit QUALPUF which is based on static random access memory (SRAM) for low-power portable electronic devices and then shows the post-layout simulation and measurement results. To evaluate the uniqueness and reliability, the 4-bit QUALPUF is implemented in 0.18 $$\upmu$$ μ m standard CMOS process with 1.8 V supply voltage. The 4-bit QUALPUF occupies 58.7$$\times$$ × 15.7 $$\upmu \mathrm {m}^{2}$$ μ m 2 of layout area. The post-layout simulation results illustrate that the uniqueness calculated from the inter-die HDs of the 4-bit QUALPUF is 47.58%, the average reliability is 95.10%, and the the energy dissipation is 29.73 fJ/cycle/bit. The functional measurement results of the fabricated chip are the same as the post-layout simulation results.


SPIN ◽  
2012 ◽  
Vol 02 (03) ◽  
pp. 1240004 ◽  
Author(s):  
NIAN X. SUN ◽  
GOPALAN SRINIVASAN

Multiferroic materials and devices have attracted intensified recent interests due to the demonstrated strong magnetoelectric (ME) coupling in new multiferroic materials and devices with unique functionalities and superior performance characteristics. Strong ME coupling has been demonstrated in a variety of multiferroic heterostructures, including bulk magnetic on ferro/piezoelectric multiferroic heterostructures, magnetic film on ferro/piezoelectric slab multiferroic heterostructures, thin film multiferroic heterostructures, etc. Different multiferroic devices have been demonstrated, which include magnetic sensors, energy harvesters, and voltage tunable multiferroic RF/microwave devices which are compact, lightweight, and power efficient. In this progress report, we cover the most recent progress on multiferroic heterostructures and devices with a focus on voltage tunable multiferroic heterostructures and devices with strong converse ME coupling. Recent progress on magnetic-field tunable RF/microwave devices are also covered, including novel non-reciprocal tunable bandpass filters with ultra wideband isolation, compact, low loss and high power handling phase shifters, etc. These novel tunable multiferroic heterostructures and devices and tunable magnetic devices provide great opportunities for next generation reconfigurable RF/microwave communication systems and radars, Spintronics, magnetic field sensing, etc.


2019 ◽  
Vol 17 ◽  
pp. 145-150
Author(s):  
Markus Scholl ◽  
Ralf Wunderlich ◽  
Stefan Heinen

Abstract. This paper presents a highly efficient digital frequency calibration method for ultra-low-power oscillators in wireless communication systems. This calibration method locks the ultra-low-power oscillator's output frequency to the reference clock of the wireless transceiver during its send- and receive-state to achieve frequency stability over process variation and temperature drifts. The introduced calibration scheme offers high jitter immunity and short locking periods overcoming frequency calibration errors for typical ultra-low-power oscillator's by utilizing non-linear segmented feedback levels. In measurements the proposed calibration method improves the frequency stability of an ultra-low-power 32 kHz oscillator from 53 to 10 ppm ∘C−1 over a wide temperature range for temperature drifts of less than 1 ∘C s−1 with an estimated power consumption of 185 nW while coping with relocking periods of 7 ms.


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