Abstract: According to an example embodiment, a method (100) for simulating a quantum operator of a bosonic quantum system is provided, the method (100) comprising: obtaining (102) a first representation that defines the quantum operator in a first operator basis using a first sequence of expansion coefficients; transforming (104), via applying a first transformation on the first sequence of expansion coefficients, the first representation into a second representation that defines the quantum operator in a first function basis using a second sequence of expansion coefficients; decomposing (106) the second representation into a third representation that defines the quantum operator as a linear combination of terms that each comprise a sum of a product of two component functions and a residual function using the second sequence of expansion coefficients, wherein the two component functions and the residual function of each term constitute a respective independent set of functions and are represented in second function ba

Abstract: For reading out a state of a qubit, a readout input waveform is injected into a system that comprises an information storage element for storing the state of the qubit and a readout resonator that is electromagnetically coupled to said information storage element. A readout output waveform is extracted from said system and detected. The injection of the readout input waveform takes place through an excitation port that is also used to inject excitation waveforms to the information storage element for affecting the state of the qubit. A phase of the readout input waveform is controllably shifted in the course of injecting it into the system.

Abstract: For reading out a state of a qubit, a readout input waveform is injected into a system that comprises an information storage element for storing the state of the qubit and a readout resonator that is electromagnetically coupled to said information storage element. A readout output waveform is extracted from said system and detected. The injection of the readout input waveform takes place through an excitation port that is also used to inject excitation waveforms to the information storage element for affecting the state of the qubit. A phase of the readout input waveform is controllably shifted in the course of injecting it into the system.