The discovery of materials with non-trivial topological properties has led to the realization of novel Josephson junctions with anomalous properties. In particular, it has been proposed that in some conditions such junctions can be in a superconducting topological state. In this work we present results for Josephson junctions based on three different heterostructures: Al/InAs, W/BiSb, and Al/Cd3As2. Junctions based on each of these heterostructures are predicted to have unique properties, and can in principle be tuned into a topological state, due to the fact that InAs has a very strong spin-orbit coupling, BiSb is a topological insulator, and Cd3As2 is a Dirac semimetal. We show how features of the Shapiro steps of the current-voltage characteristic under microwave radiation can be used, in realistic conditions, to extract detailed information on the microscopic electronic properties of the junctions, such as their topological state, and the presence of Leggett modes in the superconducting leads. We then discuss how in SQUIDs formed by some of the studied Josephson junctions a microwave-tunable diode effect might be present.
Recently, the Josephson diode effect (JDE) in Josephson junctions (JJs) has attracted a great deal of interests. It is expected that JDE may find important applications such as passive on-chip gyrators and circulators. Such devices would be particularly impactful in quantum information applications.
JDE occurs when both inversion symmetry and time reversal symmetry (TRS) are broken. Normally, external magnetic fields or magnetic heterostructures are exploited to break TRS. In this talk, we will present our recent observation of zero-magnetic-field JDE in topological superconducting quantum interference devices (SQUIDs) made of Dirac semimetal Cd3As2. We argue that a phase coupling between the surface and bulk superconducting channels, a unique phenomenon recently identified in the observations of fractional Josephson effect and Leggett modes in Cd3As2, can break TRS and, therefore, give rise to the zero-field JDE. We further show that the efficiency of the JDE can be readily varied by the geometry of JJ arms in the SQUIDs. Our results should have important implications in superconducting electronic circuit applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.