Article
Materials Science, Multidisciplinary
Pawel Steblinski, Tomasz Blachowicz, Andrea Ehrmann
Summary: This article presents micro-magnetic simulations to analyze the energy density of nano-scaled iron spheres. The effects of different coatings and thicknesses on energy uniformity, as well as the relationship between droplet size and magnetization distribution, were investigated. The study reveals that oxide-coated spheres can be placed closer together in comparison to non-coated spheres.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Thien An Nguyen, Jaejin Lee
Summary: Bit-patterned media recording (BPMR) is a promising technology for increasing the areal density (AD) of magnetic data storage systems. In this study, the maximum a posteriori (MAP) algorithm is proposed to improve the serial detection method and address the issues of 2D interference and track mis-registration (TMR) in BPMR.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Seongkwon Jeong, Jaejin Lee
Summary: In this study, a bit-flipping scheme using the K-means algorithm for bit-patterned media recording (BPMR) system is proposed to increase the areal density of hard disk drives. The scheme reduces the distance between islands storing 1 bit and utilizes neighboring information to improve performance.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Nanoscience & Nanotechnology
S. Sokjabok, M. Mattayakan, C. Buajong, S. Koonkarnkhai, P. Kovintavewat, C. Warisarn
Summary: The reduction in track width of ultra-high density magnetic recording leads to an increase in areal density, but also brings about severe inter-symbol interference and inter-track interference. To address these issues, a single-reader/two-track reading technique and constrained coding schemes are proposed, showing superior performance in mitigating ISI and ITI effects compared to conventional systems.
Article
Chemistry, Multidisciplinary
Seongkwon Jeong, Jaejin Lee
Summary: This study proposes a modulation decoding method based on the K-means algorithm to improve decoding capabilities in bit-patterned media recording systems. Increasing the areal density makes it more difficult to detect data due to the influence of intersymbol interference (ISI) and intertrack interference (ITI), but modulation coding can prevent severe ISI and ITI caused by specific data patterns.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Yuhui Wang, Ying Zheng, Ziyi Zhong, Zijun Wang, Yongfeng Liang, Pingping Wu
Summary: The magnetic properties of a core-shell type exchange coupled composite structure were studied using micromagnetic simulation. Switching loops with magnetic domain structure evolution were demonstrated and a switching type diagram was constructed. The effects of switching type and composite structure on coercivity and remanent magnetization were predicted and discussed. The core-shell type FePt/Fe composite structure film was found to have a significant advantage in designing high-density storage devices at the nanoscale.
Article
Chemistry, Multidisciplinary
Gyuyeol Kong, Minchae Jung
Summary: This paper proposes a tabu search aided multi-track detection scheme for bit patterned magnetic recording. The proposed scheme adopts a simplified multi-track detector with a two-dimensional generalized partial response target, uses a priori information, and employs a reliability test and a tabu search detector. The proposed scheme processes signals in three stages, and achieves better performance compared to conventional schemes.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Multidisciplinary
Seongkwon Jeong, Jaejin Lee
Summary: This study investigates the electronic structure and magnetic properties of potential two-dimensional material MnPS3 using density functional theory. The results reveal its semiconductor nature and antiferromagnetic properties, providing a theoretical basis for its applications in electronic and magnetic devices.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Multidisciplinary
Thien An Nguyen, Jaejin Lee
Summary: Bit-patterned media recording (BPMR) is proposed as a candidate solution for addressing superparamagnetism issues in magnetic data storage. This study focuses on reducing the distance between magnetic islands in BPMR to increase the areal density, while also addressing the increased two-dimensional interference. A new estimator based on the 2D Viterbi algorithm (VA) with reduced states is proposed to predict interference from neighboring tracks. Simulation results demonstrate the superiority of this model compared to previous models.
APPLIED SCIENCES-BASEL
(2022)
Article
Computer Science, Information Systems
Thien An Nguyen, Jaejin Lee
Summary: This article examines a new distribution of bit-patterned media recording called staggered BPMR. By dividing the interference into three parts and using three one-dimensional detectors, the proposed model improves the detection performance of the main data. Simulation results demonstrate that this model outperforms previous studies.
Article
Chemistry, Multidisciplinary
Thien An Nguyen, Jaejin Lee
Summary: Ultra-high density data storage, specifically using bit-pattern media recording (BPMR), is crucial due to the increasing volumes of data. A neural network model for noise prediction has been proposed to improve the performance of serial detection, resulting in approximately 1 dB gain in bit error rate (BER) compared to the model with a feedback line.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Electrical & Electronic
Jialu Yin, Jia Yuan, Zhi Li, Shushan Qiao
Summary: This paper proposes a two-dimension half-select free 12T SRAM cell suitable for the bit-interleaving structure. The proposed cell increases the write margin and read static noise margin through a data-aware power-cutting method and a decoupled read port. It also reduces multi-bits soft errors effectively by implementing two technologies for two-dimension half-select free. Monte Carlo simulations confirm the robustness of the cell, and it achieves better performance compared to the 6T cell at 0.4V.
IEICE ELECTRONICS EXPRESS
(2022)
Article
Physics, Multidisciplinary
Wei Chen, Jincai Chen, Zongsong Gan, Yaxiong Ma, Ke Luo, Zhenxing Huang, Yang He, Ping Lu
Summary: The semi-circle resonator system proposed as the light delivery system for HAMR can provide a stable enhanced optical field to excite the localized surface plasmon of NFT without complex focusing lenses or external controls. Combined with bit-patterned media, the performance can be improved several times than the thin-film structure.
Article
Engineering, Electrical & Electronic
Seongkwon Jeong, Jaejin Lee
Summary: The study proposes using extrinsic information obtained from an MLP equalizer to improve the detection performance of BPMR in PRML detector, showing better performance compared to both MLP equalizer and conventional PRML alone. The proposed detector also provides improved performance when track misregistration occurs.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Chemistry, Analytical
Pirat Khunkitti, Naruemon Wannawong, Chavakon Jongjaihan, Apirat Siritaratiwat, Anan Kruesubthaworn, Arkom Kaewrawang
Summary: This study introduces exchange-coupled composite bit-patterned media (ECC-BPM) combined with microwave-assisted magnetic recording (MAMR) to enhance the writeability of magnetic media at a recording density of 4 Tb/in^2. By evaluating the suitable microwave field frequency and exchange coupling values between magnetic dots in the proposed media, significant reductions in switching field were achieved compared to conventional media, further decreased by utilizing MAMR technology.
