Nonlinear dynamics of josephson junction chains and superconducting resonators
Başlık çevirisi mevcut değil.
- Tez No: 401071
- Danışmanlar: PROF. DAVID B. HAVILAND
- Tez Türü: Doktora
- Konular: Fizik ve Fizik Mühendisliği, Physics and Physics Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2013
- Dil: İngilizce
- Üniversite: KTH-Kungliga Tekniska Högskolan (Royal Institute of Technology)
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Belirtilmemiş.
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 125
Özet
Özet yok.
Özet (Çeviri)
This thesis presents the results of the experimental studies on two kind of Superconducting circuits: one-dimensional Josephson junction chains and superconducting coplanar waveguide (CPW) resonators. One-dimensional Josephson junction chains are constructed by connecting many Superconducting quantum interference devices (SQUIDs) in series. We have studied DC transport properties of the SQUID chains and model their nonlinear dynamics with Thermally Activated Phase-Slips (TAPS). Experimental and simulated results showed qualitative agreement revealing the existence of a uniform phase-slipping and phase-sticking process which results in a voltageindependent current on the dissipative branch of the current-voltage characteristics (IVC). By modulating the effective Josephson coupling energy of the SQUIDs (EJ ) with an external magnetic field, we found that the ratio EJ/EC is a decisive factor in determining the qualitative shape of the IVC. A quantum phase transition between incoherent Quantum Phase Slip, QPS (supercurrent branch with a finite slope) to coherent QPS (IVC with well-developed Coulomb blockade) via an intermediate state (supercurrent branch with a remnant of Coulomb blockade) is observed as the EJ/EC ratio is tuned. This transition from incoherent QPS to the intermediate-state happens around R0 = RQ (RQ = h/4e2 = 6.45k ). We also fabricated structured chains where a SQUID at the middle of the chain (central SQUID) has different junction size and loop area compared to other SQUIDs in the chain. Results showed that with these structured chains it is possible to localize and tune the amplitude of both TAPS and QPS at the central SQUID. The second part of the thesis describes the fabrication process and the measurement results of superconducting CPW resonators. Resonators with different design parameters were fabricated and measured. The transmission spectra showed quality factors up to, Q 5×105. We have observed bending of the resonance curves to the lower frequencies due to existence of a nonlinear kinetic inductance. The origin of the nonlinear kinetic inductance is the nonlinear relation between supercurrent density, Js and superfluid velocity, vs, of the charge carriers on the center line of the resonators. A simple model based on the Ginzburg-Landau theory is used in order to explain observed nonlinear kinetic inductance and estimates using this model showed good agreement with the experimental results.
Benzer Tezler
- Transition dynamics of single- and double Josephson junctions formed by spatially coupled soliton and surface plasmons
Uzamsal etkileşim içinde bulunan soliton ve yüzey plazmonlarının oluşturduğu tek ve çift Josephson eklemlerinin geçiş dinamiği
GÜNEŞ AYDINDOĞAN
Doktora
İngilizce
2017
Fizik ve Fizik MühendisliğiKoç ÜniversitesiFizik Ana Bilim Dalı
DOÇ. DR. KAAN GÜVEN
- Nonlinear dynamical aspects of the dielectric waveguide surface plasmon josephson junction
Dielektrik dalga kılavuz-yüzey plazmonu Josephson ekleminin doğrusal olmayan dinamik özellikleri
YASA EKŞİOĞLU ÖZOK
Doktora
İngilizce
2011
Fizik ve Fizik MühendisliğiKoç ÜniversitesiFizik Ana Bilim Dalı
DOÇ. DR. KAAN GÜVEN
- Dynamics of optical soliton and surface plasmon in dielectric-metal and dielectric-metal-dielectric interfaces
Dielektrik-metal and dielektrik-metal-dielektrik arayüzlerde optik soliton ve yüzey plazmonlarının dinamiği
GÜNEŞ AYDINDOĞAN
Yüksek Lisans
İngilizce
2012
Fizik ve Fizik MühendisliğiKoç ÜniversitesiFizik Ana Bilim Dalı
YRD. DOÇ. DR. KAAN GÜVEN
- Nonlinear dynamics of the Black sea ecosystem and its response to anthropogenic and climate variations
Karadeniz ekosisteminin doğrusal olmayan dinamikleri ve antropojenik ve iklimsel değişkenlere olan tepkisi
EKİN AKOĞLU
Doktora
İngilizce
2013
Deniz BilimleriOrta Doğu Teknik ÜniversitesiDeniz Biyolojisi ve Balıkçılık Ana Bilim Dalı
YRD. DOÇ. DR. BARIŞ SALİHOĞLU
