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"This thesis presents a novel method for fabricating the smallest superconducting quantum interference device (SQUID) that resides on the apex of a very sharp tip. The nanoSQUID-on-tip displays a characteristic size down to 100 nm and a field sensitivity of 10^-3 Gauss/Hz^(1/2). A scanning SQUID microsope was constructed by gluing the nanoSQUID-on-tip to a quartz tuning-fork. This enabled the nanoSQUID to be scanned within nanometers of the sample surface, providing simultaneous images of sample topography and the magnetic field distribution. This microscope represents a significant improvement over the existing scanning SQUID techniques and is expected to be able to image the spin of a single electron."

"Bahan superkonduktor BPSCCO-2212 dengan kadar CaCO3 1,0 dan 1,10 fraksi mol telah disintesis dengan metode reaksi padatan (solid state reaction method). Sintesis dilakukan selama 10 jam pada suhu kalsinasi (Tk) 800oC dan sintering selama 20 jam dengan suhu (Ts) 830oC. Tujuan penelitian untuk mengetahui pengaruh variasi doping Pb dan Ca terhadap tingkat kemurnian fase superkonduktor Bi-2212 yang terbentuk (fraksi volume (Fv), derajat orientasi (P), dan impuritas (I)). Hasil sintesis dikarakterisasi menggunakan XRD (X-Ray Diffraction) dan SEM (Scanning Electron Microscopy). Hasil analisis profil XRD oleh sofware Celref menunjukkan variasi doping Pb cenderung meningkatkan fraksi volume (Fv) BSCCO-2212. Fraksi volume (Fv) pada kadar Ca = 1,0 dan Pb = 0 diperoleh 72,60%, Pb = 0,2, diperoleh 74,10%, Pb = 0,4 diperoleh 60,48 %, dan Pb = 0,6 diperoleh 61,90 %. Sedangkan derajat orientasi (P) tertinggi diperoleh dengan doping Pb = 0,6 sebesar 30,62%. Untuk Fraksi volume (Fv) pada kadar Ca = 1,10 dan doping Pb = 0, diperoleh 65,17 %, Pb = 0,2, diperoleh 78,81%, Pb = 0,4 diperoleh 63,29%, dan Pb = 0,6, diperoleh 87,31%. Fraksi volume relatif baik pada sampel kadar Ca = 1,10 dengan doping Pb = 0,6, yaitu 87,31%. Sedangkan derajat orientasi (P) relatif baik pada sampel Ca = 1,10 tanpa doping Pb yaitu 32,76 %.

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Synthesis of BPSCCO-2212 superconducting materials with CaCO3 1,0 and 1,10 mole fraction has been done using solid reaction method. Synthesis conducted with calcination for 10 hours at temperature of 800oC and sintering for 20 hours with sintering temperature 830 0C. Variation Pb dopant was performed to determine the effect on the level of purity of the Bi-2212 superconducting phase is formed (volume fraction (Fv), the degree of orientation (P), and impurity (I)). The samples were characterized using XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy).

XRD analysis results showed variation tended to increase the value of the volume fraction (Fv). Value of the volume fraction (Fv) with Ca 1,0 and Pb = 0, obtained 72,60%, Pb = 0,2 obtained 74,10%, Pb = 0,4 obtained 60,48%, and Pb = 0,6, obtained 61.90%. While the value of highest degree of orientation (P) with Pb = 0,6 obtained 30,62%. Volume fraction (Fv) with Ca = 1,10, and dopant Pb = 0, obtained 56,17%, Pb = 0,2, obtained 78,81%, Pb = 0,4 obtained 63,29%, and Pb = 0,6, obtained 87,31%. Volume Fraction relatively well contained in Ca = 1,10 witg Pb dopant 0,6 is 87,31%. While the degree of orientation (P) is relatively well contained in the sample with Ca = 1,10 without Pb dopant is 32,76%."

"Pengendalian sistem kuantum hibrid melalui penerapan medan eksternal merupakan bidang penelitian yang berkembang pesat untuk pengembangan aplikasi dan teknologi kuantum. Kami memodelkan dan mengoptimalkan dinamika sistem kuantum hibrid yang terdiri dari dua kumpulan pusat kekosongan nitrogen (NV Centers) non-lokal dan qubit transmon superkonduktor yang dimediasi oleh dua resonator saluran transmisi.Kami menerapkan serangkaian bidang penggerak eksternal yang bergantung pada waktu dan dioptimalkan untuk meningkatkan kinerja sistem agar berfungsi sebagai transfer antar negara dengan ketelitian tinggi. Hamiltonian dari resonator saluran transmisi yang digerakkan secara eksternal dimodelkan dengan mempertimbangkan transmon non-linier. Simulasi numerik sistem dilakukan dengan menggunakan parameter optimal dari bidang eksternal. Dengan menerapkan pulsa yang dioptimalkan, kami telah meningkatkan fidelitas transfer status dari 0,7 menjadi 1,0 dalam waktu 100 ns. Dengan memvariasikan nilai setengah maksimum gelombang penuh (FWHM) dari pulsa Gaussian, hal ini mengakibatkan penurunan amplitudo keadaan osilasi cepat dari ansambel transmon dan kekosongan nitrogen. Pulsa eksternal yang dioptimalkan ini juga menciptakan hubungan yang kuat antara komponen-komponen sistem kuantum fisik yang sedang dipertimbangkan, yang pada akhirnya akan meningkatkan fidelitas sistem dalam waktu yang relatif lebih cepat.

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The control of hybrid quantum systems via the application of external fields is rapidly evolving field of research for the development of quantum applications and technologies. We model and optimize the dynamics of a hybrid quantum system consists of two non-local ensembles of nitrogen-vacancy centers and a superconducting transmon qubit mediated by two transmission line resonators. We apply a set of optimized time-dependent external driving field to enhance the system performance to function as a high fidelity state-to-state transfer. The Hamiltonian of the externally driven transmission line resonators is modelled by considering the non-linear transmons. The numerical simulation of the system is done using the optimized parameters of the external fields. By applying the optimized pulses, we have increased the fidelity of the state transfer from 0.7 to 1.0 within 100 ns. By varying the full wave half maxima value (FWHM) of the Gaussian pulse, it results in decreasing the amplitude of the fast oscillating states of the transmon and nitrogen-vacancy ensembles. These optimized external pulses also created a strong coupling between the components of under-consideration physical quantum system, which will eventually increase the fidelity of the system in a relatively faster time."

"Telah dilakukan sintesis bahan superkonduktor doping elektron Eu2-xCexCuO4+α-δ (ECCO) dengan metode reaksi padatan. Variasi dari doping Cerium ke dalam senyawa induk Eu2CuO4 serta variasi nilai δ, akan merubah nilai parameter kisi, resistivitas, dan suseptibilitas. Dari karakterisasi XRD, nilai parameter kisi pada sumbu c akan berkurang dengan meningkatnya konten Cerium. Pada sumbu a, parameter kisi bernilai maksimum pada x = 0.15. Dari uji resistivitas dan suseptibilitas, sifat superkonduktor dengan Tc ~ 13 K ditemukan pada bahan x = 0.15 dengan δ = 0.09. Namun demikian, sifat superkonduktivitas sampel dengan x = 0.11 dan x = 0.19 tidak terlihat.

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Electron doped Superconductor Eu2-xCexCuO4+α-δ (ECCO) has been syntesized using sp;od state reaction method. Variation of Cerium doping into mother compound Eu2CuO4 and the value of δ, will change the value of lattice parameter, resistivity, and susceptibility. From XRD characterization, the value of lattice parameter in c axis decreases with increasing Cerium content. In a axis, the lattice parameter has been found to be maximum in x = 0.15. From resistivity and susceptibility measurements, it is found that superconducting properties with Tc ~ 13 K are observed at x = 0.15 with δ = 0.09. However, in the sample with x = 0.11 and x = 0.19, superconducting properties are not observed."