Micro-SQUIDs based on MgB₂nano-bridges for NEMS readout

Abstract

We show the results obtained from the fabrication and characterisation of MgB2 loops with two nano-bridges as superconducting weak links. These ring structures are made to operate as superconducting quantum interference devices and are investigated as readout system for cryogenics NEMS resonators. The nano-constrictions are fabricated by EBL and ion beam milling. The SQUIDs are characterised at different temperatures and measurements of the noise levels have been performed. The devices show high critical current densities and voltage modulations under applied magnetic field, close to the critical temperatures.

Recent trends and perspectives of nanoSQUIDs: introduction to ‘Focus on nanoSQUIDs and their applications’

“…In addition to the simplicity of the fabrication process based on a patterning of a single layer, nanoSQUIDs based on nanobridges offer the possibility of operation in a high magnetic field since the nanobridges are insensitive to the applied magnetic field on account of their small cross-sectional area. In particular, recent nanoSQUIDs based on niobium nitride and MgB 2 allow for operation in high magnetic fields and in a wider range of temperatures [7,8]. Often, nanoSQUIDs based on nanobridges show a hysteretic behaviour at T4.2 K, so the SQUID cannot be used as a magnetic flux to voltage converter.…”

Mg Difüzyonu Tekniği ile Türkiye’de Saflaştırılmış Bor Kullanılarak Üretilen MgB2 için B Saflığının Süperiletkenlik Özellikleri Üzerine Etkisi

“…MgB2 süperiletkeninin ilgi çeken özellikleri (i) basit kimyasal yapısı, (ii) nispeten kolay üretimi, (iii) kimyasal maliyetinin düşük olması [2], (iv) polikristal olarak da çalışabilmesi [3], (v) farklı şekil ve boyutlarda üretilebiliyor olması (külçe, silindir, halka, tel, şerit) [4][5], (vi) tane sınırlarının çivilenme merkezi görevi görmesi [6][7], (vii) daha büyük manyetik alanları tuzaklayabiliyor olması [8] şeklinde sıralanabilir. Özellikle Manyetik Rezonans Görüntüleme-MRI [9][10][11][12][13], Hatalı Akım Sınırlayıcı-FCL [14][15][16], Süperiletken Kuantum Girişim Cihazı SQUID [17], elektrik motoru ve jeneratörler [18][19] gibi uygulamalar için, uygulamanın ihtiyacına yönelik MgB2 malzeme özelliklerinin geliştirilmesi yönünde birçok araştırma yapılmıştır [20][21][22][23]. MgB2 uzay araştırmalarında, ulaşımda, tıpta, enerjide ve hafif malzeme gerektiren diğer alanlarda hafif bir malzeme oluşu sebebiyle de ilgi çekmektedir.…”

Existence of Shapiro Steps in the Dissipative Regime in Superconducting Weak Links

“…The majority of work in the area has focussed on development and optimization of micron-sized superconducting quantum interference devices (nanoSQUIDs), which are implemented using two WLs [2]. NanoSQUIDs can be used for many applications including single magnetic nanoparticle detection [3], scanning SQUID microscopy for imaging of nanoscale phenomena [4][5][6] and nanoelectromechanical system (NEMS) readout [7,8]. Aside from magnetometer-based applications, WL Josephson junctions could be used in place of traditional junctions for single flux quantum (SFQ) circuits [9], and Josephson voltage standards used in the metrology community [10,11].…”