scholarly journals Photon-Assisted Seebeck Effect in a Quantum Dot Coupled to Majorana Zero Modes

2021 ◽  
Vol 9 ◽  
Author(s):  
Tian-Yu He ◽  
Hailing Sun ◽  
Guofu Zhou
Keyword(s):  
Quantum Dot ◽  
Electrical Conductance ◽  
Seebeck Effect ◽  
Function Technique ◽  
Zero Modes ◽  
Photon Field ◽  
Different Temperatures ◽  
Left And Right ◽  
Assisted Tunneling ◽  
Non Equilibrium Green’S Function

The Seebeck effect is investigated within the framework of a non-equilibrium Green's function technique in a quantum dot (QD) sandwiched between the left and right leads held at different temperatures. We consider that the QD is shelled by a photon field and is side-coupled to a topological superconductor nanowire hosting Majorana zero modes (MZMs). It is found that the thermopower (Seebeck coefficient) can be obviously enhanced by weak QD-MZMs coupling at low temperatures, in addition to its sign reversion that may be used for detecting the existence of MZMs. In the presence of a photon field, the thermopower can be further enhanced due to decreased electrical conductance when electrons' transport probability through each channel is reduced by photon-assisted tunneling (PAT). The hybridization between the MZMs will also induce sign reversion of the thermopower in the absence of a photon field, whereas it has less impact on the thermopower when the QD is shelled by the photon field.

Thermoelectric Transport in a Double-Quantum-Dot Coupled to Majorana Zero Modes

2021 ◽  
Vol 16 (5) ◽  
pp. 753-761
Author(s):  
Jing Wang ◽  
Lian-Liang Sun ◽  
Feng Chi ◽  
Zhen-Guo Fu
Keyword(s):  
Quantum Dot ◽  
Function Technique ◽  
Double Quantum ◽  
Thermoelectric Effect ◽  
Thermoelectric Transport ◽  
Zero Modes ◽  
Symmetric Point ◽  
Double Quantum Dot ◽  
Sign Change ◽  
Non Equilibrium Green’S Function

Thermoelectric transport through a double-quantum-dot (DQD) connected to the left and right leads is theoretically investigated in the framework of non-equilibrium Green’s function technique. We consider that the dots are also coupled to Majorana zero modes (MZMs) prepared at the two ends of a topological superconductor nanowire. It is found that the sign change of thermopower, which is promising in the detection of MZMs, can be realized by tuning several system’s parameters related to the MZMs, such as the coupling strength between the dots and the MZMs, the direct coupling between the MZMs, or even the magnetic flux penetrating through the structure. The above parameters also lead to significant enhancement of the thermopower and thermoelectric figure of merit (FOM), which indicates the conversion efficiency between heat and electrical energies. We also find that in this DQD system, both the thermopower and FOM are simultaneously enhanced by the MZMs around the electron-hole symmetric point, an ideal phenomenon in applications of thermoelectric effect. In addition, the thermoelectric effect is remarkably enhanced by the direct hybridization between the MZMs, which is very different from the case in single-dot structure.

Conductance through a parallel-coupled double quantum dot with a side-coupled quantum dot system

2017 ◽  
Vol 31 (09) ◽  
pp. 1750095 ◽  
Author(s):  
Zelong He ◽  
Jiyuan Bai ◽  
Cheng Ma
Keyword(s):  
Quantum Dot ◽  
Coupling Strength ◽  
Fano Resonance ◽  
Numerical Results ◽  
Function Technique ◽  
Double Quantum ◽  
Double Quantum Dot ◽  
Couple Quantum ◽  
Interdot Coupling ◽  
Non Equilibrium Green’S Function

Using the non-equilibrium Green’s function technique, conductance through a parallel-coupled double quantum dot (PCDQD) with a side-coupled quantum dot system is investigated. The evolution of the conductance strongly depends on the coupling between the side-coupled quantum dot and PCDQD. Moreover, the conductance as a function of the level of side-couple quantum dot is investigated. Numerical results indicate the lineshape of Fano resonance can be modulated by adjusting the interdot coupling strength.

scholarly journals Effect of Growth Temperature on the Characteristics of CsPbI3-Quantum Dots Doped Perovskite Film

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4439
Author(s):  
Shui-Yang Lien ◽  
Yu-Hao Chen ◽  
Wen-Ray Chen ◽  
Chuan-Hsi Liu ◽  
Chien-Jung Huang
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Quantum Dots ◽  
Quantum Dot ◽  
Growth Temperature ◽  
Electron Mobility ◽  
Surface Defects ◽  
Different Temperatures ◽  
Pb Doping ◽  
Pristine Film

In this study, adding CsPbI3 quantum dots to organic perovskite methylamine lead triiodide (CH3NH3PbI3) to form a doped perovskite film filmed by different temperatures was found to effectively reduce the formation of unsaturated metal Pb. Doping a small amount of CsPbI3 quantum dots could enhance thermal stability and improve surface defects. The electron mobility of the doped film was 2.5 times higher than the pristine film. This was a major breakthrough for inorganic quantum dot doped organic perovskite thin films.

Photon-assisted tunneling through a regular B-form single-stranded DNA with Majorana zero modes

2021 ◽  
Vol 415 ◽  
pp. 127655
Author(s):  
Han-Zhao Tang ◽  
Xiao-Tong Liao ◽  
Zhi-Bin Zhang ◽  
Yan-Xia Liu ◽  
Zhuo Gu
Keyword(s):  
Single Stranded Dna ◽  
Zero Modes ◽  
Assisted Tunneling

Effect of the vacancy on the electrical transport properties of boron nitride nanosheets

2021 ◽  
Author(s):  
Reza Sadeghi ◽  
Mojtaba Yaghobi ◽  
Mohammad Reza Niazian ◽  
Mohammad ali Ramzanpour
Keyword(s):  
Electrical Transport ◽  
Density Functional ◽  
Vacancy Defect ◽  
Defect Engineering ◽  
Electrical Transport Properties ◽  
Functional Theory ◽  
Crystalline Materials ◽  
The Density Functional Theory ◽  
Left And Right ◽  
Non Equilibrium Green’S Function

Abstract Vacancies occur naturally in all crystalline materials. A vacancy is a point defect in a crystal in which an atom is removed at one of the lattice sites. The defect could be imported during the synthesis of the material or be added by defect engineering. In this paper by employing the density functional theory as well as the non-equilibrium Green’s function approach, the structure and electronic properties of the perfect and defected BN nanosheet would be obtained and compared. Besides, the influence of the vacancy defect position is evaluated. For this purpose, the defect is considered at the center, left, and right hand sides of the nanosheet. It is seen that the electric current changes by changing the position of the vacancy defect, which is related to the electronic structures of BN nanosheets. In addition, the transmission and conductance for BN nanosheets with vacancy continuously change by changing the bias voltage. The obtained results can benefit the design and implementation of BN nanosheets in nanoelectronic systems and devices.

scholarly journals Efficient enhancement of the thermoelectric effect due to the Majorana zero modes coupled to one quantum-dot system

2019 ◽  
Vol 99 (19) ◽  
Author(s):  
Xiao-Qi Wang ◽  
Shu-Feng Zhang ◽  
Yu Han ◽  
Guang-Yu Yi ◽  
Wei-Jiang Gong
Keyword(s):  
Quantum Dot ◽  
Thermoelectric Effect ◽  
Zero Modes

scholarly journals Controlled and cellulose eco-friendly synthesis and characterization of Bi2O2CO3 quantum dot nanostructures (QDNSs) and drug delivery study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hojat Samarehfekri ◽  
Hamid Reza Rahimi ◽  
Mehdi Ranjbar
Keyword(s):  
Quantum Dot ◽  
Optical Band Gap ◽  
Biological Therapy ◽  
Skin Extract ◽  
Force Microscopy ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Different Temperatures ◽  
Green Capping Agent

AbstractThis work aimed to prepare solvent-free or green Bi2O2CO3 for quantum dot nanostructures (QDNSs) based on cellulose as a stabilizer and green capping agent to sorafenib delivery for liver targeting. Because the walnut tree is one of the most abundant trees in Iran, it was tried to synthesize Bi2O2CO3 QDNSs using a walnut skin extract. The saturation magnetization for Bi2O2CO3 QDNSs was calculated to be 68.1. Also, the size of products was measured at around 60–80 nm with the Debye–Scherrer equation. Moreover, the morphology, functional groups, and crystallography of the Bi2O2CO3 nanoparticles were investigated using atomic force microscopy, scanning electron microscopy, vibrating-sample magnetometer, and Uv–vis spectroscopy. The results demonstrated that Bi2O2CO3 QDNSs have opto-magnetic properties and they can be suggested as the candidate materials for the sorafenib delivery on the liver tissue. The optical band gap estimated for Bi2O2CO3 QDNSs was found to be red-shift from 3.22 eV. This study suggests the preparation of the Bi2O2CO3 QDNSs based on cellulose as new opto-magnetic materials at different temperatures of 180 °C, 200 °C, 220 °C, and 240 °C for sorafenib delivery as a type of biological therapy drug.

WIGNER THEORY OF THE NAMBU STRING: (II) THE CLOSED STRING

1992 ◽  
Vol 07 (17) ◽  
pp. 4107-4148 ◽  
Author(s):  
F. COLOMO ◽  
L. LUSANNA
Keyword(s):  
Minkowski Space ◽  
Canonical Basis ◽  
Open String ◽  
Closed String ◽  
Zero Modes ◽  
Left And Right ◽  
The One

A set of relative variables for the closed string with P2>0 is found, which has Wigner covariance properties. They allow one to obtain global Lorentz-invariant abelianizations of the constraints, like for the open string, and then global Lorentz-invariant canonically conjugated gauge variables are found. But now there are two extra zero modes in the constraints and in the gauge variables, related to the gauge arbitrariness of the origin σ0 of the circle σ∈(−n, π) embedded in Minkowski space, σ↦xμ(σ). By means of the multitemporal approach a noncanonical redundant set of Dirac observables for the left and right modes is defined; they transform as spin-1 Wigner vectors and satisfy constraints of the same kind as in σ models. The quantization is not made, because a canonical basis of observables is still lacking, but the program to be followed to find them is just the same as the one delineated for the case of the open string.

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