Browsing by Author "Di Ventra, Massimiliano"

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Exploration and characterization of the memcapacitor and memristor properties of Ni-DNA nanowire devices
(2017-09-01)
Chu, Hsueh-Liang
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Lai, Jian-Jhong
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Wu, Li-Ying
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Chang, Shen-Lin
;
Liu, Chia-Ming
A 2-mu m-long Ni ion-chelated DNA molecule (Ni-DNA) was found for the first time to possess both memcapacitor and memristor properties; this Ni-DNA molecule is known as a dual memory circuit element (memelement). As a memelement, the state of impedance on Ni-DNA is proportional to the unit number of Ni ions containing a base pair complex (Ni-bp), which is determined by the previously applied external voltage. Interestingly, the impedances of Ni-DNA change in response to a change in the sweeping frequencies of the external bias. Our simulation results also indicate that changes in the effective resistance and capacitance of Ni-bp may be attributed to changes in the Ni ion redox species in the Ni-bp of a Ni-DNA nanowire. Therefore, the working mechanism of a nanowire-type memcapacitor and memristor is revealed. In summary, the Ni-DNA nanowire is shown to be a multi-dimensional memory device, whose memory state depends on the length of DNA and applied external voltages/frequencies.
Measurement of current-induced local heating in a single molecule junction
(2006-06-01)
Huang, Zhifeng
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Xu, Bingqian
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Chen, Yuchang
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Di Ventra, Massimiliano
;
Tao, Nongjian
We have studied the current-induced local heating effects in single molecules covalently bound to two electrodes by measuring the force required to break the molecule-electrode bonds under various conditions. The breakdown process is thermally activated, which is used to extract the effective temperature of the molecular junction as a function of applied bias voltage. We have also performed first-principles calculations of both local heating and current-induced force effects, and the results are in good agreement with the experimental findings.
Programmable Redox State of the Nickel Ion Chain in DNA
(2014-02-01)
Chu, Hsueh-Liang
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Chiu, Shao-Chien
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Sung, Ching-Feng
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Tseng, Wellen
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Chang, Yu-Chuan
DNA is a nanowire in nature which chelates Ni ions and forms a conducting chain in its base-pairs (Ni-DNA). Each Ni ion in Ni-DNA exhibits low (Ni2+) or high (Ni3+) oxidation state and can be switched sequentially by applying bias voltage with different polarities and writing times. The ratio of low. and high oxidation states of Ni ions in Ni-DNA represents a programmable multistate memory system with an added capacitive component, in which multistate information can be written, read, and erased. This study also indicates that the biomolecule-based self-organized nanostructure can be used as a template for nanodevice fabrication.