Related papers: Detection of a persistent-current qubit by resonan…
Eigenstate-preserving multi-qubit parity measurements lie at the heart of stabilizer quantum error correction, which is a promising approach to mitigate the problem of decoherence in quantum computers. In this work we explore a…
We study an RF SQUID, in which a section of the loop is a freely suspended beam that is allowed to oscillate mechanically. The coupling between the RF SQUID and the mechanical resonator originates from the dependence of the total magnetic…
A method for measuring small energy level shifts in a qubit by coherent amplification of their effect is proposed. It is based on the repeated application of the same interaction pulse in two manners: with the same phase of each subsequent…
Superconducting qubits coupled to electric or nanomechanical resonators display effects previously studied in quantum electrodynamics (QED) and extensions thereof. Here we study a driven qubit coupled to a low-frequency tank circuit with…
Despite the significant progress in superconducting quantum computation over the past years, quantum state measurement still lags nearly an order of magnitude behind quantum gate operations in speed and fidelity. The main challenge is that…
In this PhD thesis, we will present the theoretical and experimental work that led to the realization of a radio-frequency circuit quantum electrodynamics system (RFcQED). In chapter 2, we provide a detailed derivation of the Hamiltonian of…
Quantum sensing takes advantage of well controlled quantum systems for performing measurements with high sensitivity and precision. We have implemented a concept for quantum sensing with arbitrary frequency resolution, independent of the…
We introduce a solid-state qubit in which exchange interactions among confined electrons provide both the static longitudinal field and the oscillatory transverse field, allowing rapid and full qubit control via rf gate-voltage pulses. We…
Cavity quantum electrodynamics (QED) with quantum emitters coupled to resonators provides a powerful platform for engineering light-matter interactions and exploring collective phenomena. In particular, superradiance, arising from…
Using a circuit QED device, we demonstrate a simple qubit measurement pulse shape that yields fast ring-up and ring-down of the readout resonator regardless of the qubit state. The pulse differs from a square pulse only by the inclusion of…
We have analyzed the interaction of a dissipative two level quantum system with high and low frequency excitation. The system is continuously and simultaneously irradiated by these two waves. If the frequency of the first signal is close to…
We show that resonant driving between the spin up and spin down states of an electron spin-qubit in a quantum dot reduces the occupancy of the dot through leakage to an appropriately tuned lead. A nearby charge sensor measuring the…
We propose a scheme to implement variable coupling between two flux qubits using the screening current response of a dc Superconducting QUantum Interference Device (SQUID). The coupling strength is adjusted by the current bias applied to…
The quantum Rabi model (QRM), composed of a qubit interacting with a quantized photonic field, is a cornerstone of quantum optics. The QRM with dominant unitary dynamics has been demonstrated in circuit quantum electrodynamics (QED)…
We demonstrate non-destructive (loss-less) fluorescent state detection of individual neutral atom qubits trapped in an optical lattice. The hyperfine state of the atom is measured with a 95% accuracy and an atom loss rate of 1%. Individual…
The readout process of a superconducting flux-qubit is theoretically analyzed in terms of the quantum dynamics of a qubit-SQUID coupled system during measurement. The quantity directly observed by the measurement is the switching current…
Resonant driving enables coherent control of quantum systems, including single and coupled qubits. From a complementary perspective, transitions of a quantum system can be exploited for the detection of microwave photons. In this work, we…
Measurement is an essential component of robust and practical quantum computation. For superconducting qubits, the measurement process involves the effective manipulation of the joint qubit-resonator dynamics, and it should ideally provide…
State readout is a key requirement for a quantum computer. For semiconductor-based qubit devices it is usually accomplished using a separate mesoscopic electrometer. Here we demonstrate a simple detection scheme in which a radio-frequency…
We have analyzed a dissipative two level quantum system (TLS) which is continuously and simultaneously irradiated by a high and low frequency excitation. The interaction of the TLS with a high frequency excitation is considered in the frame…