arXiv subjects

M. Akbari

Publications and source records attributed to M. Akbari.

5 recordsLinked to original sources

arXiv2024

Blochnium-Based Josephson Junction Parametric Amplifiers: Superior Tunability and Linearity

The weak quantum signal amplification is an essential task in quantum computing. In this study, a recently introduced structure of Josephson junctions array called Blochnium (N series Quarton structure) is utilized as a parametric amplifier. We begin by theoretical deriving the system's Lagrangian, quantum Hamiltonian, and then analyze the dynamics using the quantum Langevin equation. By transforming these equations into the Fourier domain and employing the input-output formalism, leading metric indicators of the parametric amplifier become calculated. The new proposed design offers significant advantages over traditional designs due to its ability to manipulate nonlinearity. This premier feature enhances the compression point (P1dB) of the amplifier dramatically, and also provides its tunability across a broad band. The enhanced linearity, essential for quantum applications, is achieved through effective nonlinearity management, which is theoretically derived. Also, the ability to sweep the C-band without significant spectral overlap is crucial for frequency multiplexing in scalable quantum systems. Simulation results show that Blochnium parametric amplifiers can reach to a signal gain around 25 dB with a compression point better than of -92 dBm. Therefore, our proposed parametric amplifier, with its superior degree of freedom, surpasses traditional designs like arrays of Josephson junctions, making it a highly promising candidate for advanced quantum computing applications.

quant-ph↗

arXiv2018

OD-Characterization of Some Simple Unitary Groups

The degree pattern of a finite group is the degree sequence of its prime graph in ascending order of vertices. We say that the problem of OD-characterization is solved for a finite group if we determine the number of pairwise nonisomorphic finite groups with the same order and degree pattern as the group under consideration. In this article the problem of OD-characterization is solved for some simple unitary groups. It was shown, in particular, that the simple unitary groups $U_3(q)$ and $U_4(q)$ are OD-characterizable, where $q$ is a prime power $<10^2$.

math.GR↗

arXiv2014

Experimental Investigation of Distant Cellular Interaction among Adipose Derived Stem-Cells

In addition to chemical and mechanical interactions between cells electromagnetic field produced by cells has been considered as another form of signaling for cell-cell communication. The aim of this study is evaluation of electromagnetic effects on viability of Adipose-derived stem cells (ADSCs) without co-culturing. In this study, stem cells were isolated from human adipose tissue enzymatically and proliferated in monolayer culture. Then, 5.(10^4) adipose-derived stem cells were cultured in each well of the test plate. In the first row (4 wells), ADSCs as inducer cells were cultured in DMEM1 with 10 ng/ml Fibroblast growth factor (FGF). In adjacent and the last rows, ADSCs were cultured without FGF (as detector cells). After the three and five days the viability of cells were evaluated. Moreover, ADSCs were cultured in the same conditions but the inducer cells were placed once in the UV-filter tube and once in the quartz tube to see whether there is electromagnetic interaction among cells. Inducer cells caused significant cell proliferation in adjacent row cells (p- value<0.01) in the fifth day. However, using the UV-filter tube and quartz tube both reduced the effect of inducer cells on adjacent cells significantly. As a conclusion, we could detect distant cellular interaction (DCI) among adipose derived stem cells (ADSCs), but it was not electromagnetic signaling. Our results show that ADSCs affect each other via volatile signaling as a chemical distant cellular interaction (CDCI).

q-bio.OT↗

arXiv2013

Some Quantitative Characterizations of Certain Symplectic Groups

Given a finite group $G$, denote by ${\rm D}(G)$ the degree pattern of $G$ and by ${\rm OC}(G)$ the set of all order components of $G$. Denote by $h_{\rm OD}(G)$ (resp. $h_{\rm OC}(G)$) the number of isomorphism classes of finite groups $H$ satisfying conditions $|H|=|G|$ and ${\rm D}(H)={\rm D}(G)$ (resp. ${\rm OC}(H)={\rm OC}(G)$). A finite group $G$ is called OD-characterizable (resp. OC-characterizable) if $h_{\rm OD}(G)=1$ (resp. $h_{\rm OC}(G)=1$). Let $C=C_p(2)$ be a symplectic group over binary field, for which $2^p-1>7$ is a Mersenne prime. The aim of this article is to prove that $h_{\rm OD}(C)=1=h_{\rm OC}(C)$.

math.GR↗

arXiv2003

Relativistic Distance

In this paper, we prove that two different observers don't equally measure the distance between two points A and B. For this, we introduce some postulates and obtain a new formula to show distance between A and B. In this formula, radius of universe, n, is entered such that if n tends to infinity the ordinary distance is obtained.

physics.gen-ph↗