Related papers: Parity effect in Al and Nb single electron transis…
The number of electrons in small metallic or semiconducting islands is quantized. When tunnelling is enabled via opaque barriers this number can change by an integer. In superconductors the addition is in units of two electron charges (2e),…
Parity control of superconducting islands hosting Majorana zero modes (MZMs) is required to operate topological qubits made from proximitized semiconductor nanowires. We, therefore, study parity effects in hybrid InAs-Al single-Cooper-pair…
The parity modulation of the ground state of a superconducting island is a direct consequence of the presence of the Cooper pair condensate preferring an even number of charge carriers. The addition energy of an odd, unpaired quasiparticle…
We present experiments on single Cooper-pair transistors made of two different superconducting materials. We chose Ti and Al to create an energy gap profile such that the island has a higher gap than the leads, thereby acting as a barrier…
We find that if two superconducting islands of different number parity are linked by a tunnel junction the unpaired electron in the odd island has a tendency to tunnel into the even island. This process leads to fluctuations in time of the…
Single electron tunneling into small superconducting islands is sensitive to the gap energy of the excitations created in the process and, hence, depends on the electron number parity. At low temperature the properties of the system are…
We measure the charge periodicity of Coulomb blockade conductance oscillations of a hybrid InSb-Al island as a function of gate voltage and parallel magnetic field. The periodicity changes from $2e$ to $1e$ at a gate-dependent value of the…
We study a Cooper-pair transistor realized by two Josephson weak links that enclose a superconducting island in an InSb-Al hybrid nanowire. When the nanowire is subject to a magnetic field, isolated subgap levels arise in the…
Deep submicron Al-AlOx-Nb tunnel junctions and single electron transistors with niobium islands were fabricated by electron beam gun shadow evaporation. Using stencil masks consisting of the thermostable polymer polyethersulfone (PES) and…
Transport properties of ferromagnetic/non-magnetic/ferromagnetic single electron transistors are investigated as a function of external magnetic field, temperature, bias and gate voltage. By designing the magnetic electrodes to have…
We report on the effect of the back-action of a Single Cooper Pair Transistor electrometer (E) on the measurement of charge on the island of a superconducting box (B). The charge is e-periodic in the gate bias of B when E is operated near…
We have fabricated and measured superconducting single-electron transistors with Al leads and Nb islands. At bias voltages below the gap of Nb we observe clear signatures of resonant tunneling of Cooper pairs, and of Coulomb blockade of the…
The low-frequency noise figures of single-electron transistors (electrometers) of traditional planar and new stacked geometry were compared. We observed a correlation between the charge noise and the contact area of the transistor island…
We present a method to measure the critical temperature of the island of a superconducting single electron transistor. The method is based on a sharp change in the slope of the zero-bias conductance as a function of temperature. We have…
We present a superconducting device showing a clear parity effect in the number of electrons, even when there is, on average, a single nonequilibrium quasiparticle present and the parity of the island switches due to quasiparticles…
We investigate a non-equilibrium aspect of the current-driven superconducting-normal phase transition in floating Al islands of epitaxial full-shell Al/InAs nanowires. Within a transition region discontinuous voltage jumps and hysteretic…
It is well known that the transport properties of single-electron transistors with a superconducting island and normal-conducting leads (NSN SET) may depend on whether or not there is a single quasiparticle on the island. This parity effect…
We have measured the Cooper Pair Transistor (CPT) in a tunable electromagnetic environment consisting of four one-dimensional SQUID arrays. The transport properties of the CPT in the high impedance limit, Z_env>>R_Q=6.45~k\Omega, are…
We study the effects of random nonmagnetic impurities on superconducting transition temperature $T_c$ in a Cu-doped Bi$_2$Se$_3$, for which four types of pair potentials have been proposed. Although all the candidates belong to $s$-wave…
We study a Cooper pair transistor realized by a mesoscopic superconductor island that couples to a pair of $s$-wave superconducting leads. For a trivial island, the critical supercurrent between the leads exhibits a well-known…