  We propose a transistor-like circuit including two serially connected
segments of a narrow superconducting nanowire joint by a wider segment with a
capacitively coupled gate in between. This circuit is made of amorphous NbSi
film and embedded in a network of on-chip Cr microresistors ensuring a
sufficiently high external electromagnetic impedance. Assuming a virtual regime
of quantum phase slips (QPS)in two narrow segments of the wire, leading to
quantum interference of voltages on these segments, this circuit is dual to the
dc SQUID. Our samples demonstrated appreciable Coulomb blockade voltage (analog
of critical current of the SQUIDs) and periodic modulation of this blockade by
an electrostatic gate (analog of flux modulation in the SQUIDs). The model of
this QPS transistor is discussed.
