We report a new type of single-electron transistor (SET) comprising two highly resistive Cr thin-film strips ($\sim1$ $\mu$m long) connecting a $1 \mu$m-long Al island to two Al outer electrodes. These resistors replace small-area oxide tunnel junctions of traditional SETs. Our transistor with a total asymptotic resistance of $110$ k$\Omega$ showed a very sharp Coulomb blockade and reproducible, deep and strictly eperiodic gate modulation in wide ranges of bias currents $I$ and gate voltages $V_g$. In the Coulomb blockade region ($|V|\leqslant$ about $0.5$ mV), we observed a strong suppression of the co-tunneling current allowing appreciable modulation curves $V(V_g)$ to be measured at currents $I$ as low as $100$ fA. The noise figure of our SET was found to be similar to that of typical Al/AlO$_x$/Al single-electron transistors, viz. $\delta Q\approx5\times 10^{-4}e/\sqrt{\mathrm{Hz}}$ at $10$ Hz.

RT Journal
T1 Metallic single-electron transistor without traditional tunnel barriers
A1 Krupenin,V.A.
A1 Zorin,A.B.
A1 Presnov,D.E.
A1 Savvateev,M.N.
A1 Niemeyer,J.
PB Uspekhi Fizicheskikh Nauk
PY 2001
FD 10 Sup, 2001
JF Uspekhi Fizicheskikh Nauk
JO Usp. Fiz. Nauk
VO 171
IS 13
SP 113-116
DO 10.1070/1063-7869/44/10S/S25
LK https://ufn.ru/ru/articles/2001/13/y/