Related papers: Probing interacting two-level systems with rare-ea…

Atomic sized two-level systems (TLSs) in amorphous dielectrics are known as a major source of loss in superconducting devices. In addition, individual TLS are known to induce large frequency shifts due to strong coupling to the devices.…

We present an absorption line analysis of the Lyman limit system (LLS) at z=3.55 in our Magellan/MIKE spectrum of PKS2000-330. Our analysis of the Lyman limit and full HI Lyman series constrains the total HI column density of the LLS (N_HI…

The low temperature properties of amorphous solids are usually explained in terms of atomic-scale tunneling two level systems (TLS). For almost 20 years, individual TLS have been probed in insulating layers of superconducting quantum…

We report an optical homogeneous linewidth of 580 $\pm$ 20 Hz of Er$^{3+}$:Y$_2$O$_3$ ceramics at millikelvin temperatures, narrowest so far in rare-earth doped ceramics. We show slow spectral diffusion of $\sim$2 kHz over a millisecond…

Quantum state lifetimes $T_2$, or equivalently homogeneous linewidths $\Gamma_h = 1/\pi T_2$, are a key parameter for understanding decoherence processes in quantum systems and assessing their potential for applications in quantum…

In a number of recent experiments with microwave high quality superconducting coplanar waveguide (CPW) resonators an anomalously weak power dependence of the quality factor has been observed. We argue that this observation implies that the…

The proper functioning of some micro-fabricated novel quantum devices, such as superconducting resonators and qubits, is severely affected by the presence of parasitic structural material defects known as tunneling two-level-systems (TLS).…

Simultaneous measurements of the intensity and phase of a probe wave reflected from an interface between silica and elemental alpha-gallium reveal its very strong optical nonlinearity, affecting both these parameters of the reflected wave.…

Rare-earth (RE) ion doped nano-materials are promising candidates for a range of quantum technology applications. Among RE ions, the so-called Kramers' ions possess spin transitions in the GHz range at low magnetic fields, which allows for…

Superconducting resonators are widely used in many applications such as qubit readout for quantum computing, and kinetic inductance detectors. These resonators are susceptible to numerous loss and noise mechanisms, especially the…

We use coherent backscattering (CBS) of light by cold Strontium atoms to study the mutual coherence of light waves in the multiple scattering regime. As the probe light intensity is increased, the atomic optical transition starts to be…

Two-level system (TLS) defects in dielectrics are known to limit the performance of electronic devices. We study TLS using millikelvin microwave loss measurements of three atomic layer deposited (ALD) oxide films--crystalline BeO…

Tunneling and Coulomb drag are sensitive probes of spontaneous interlayer phase coherence in bilayer two-dimensional electron systems at total Landau level filling factor $\nu_T = 1$. We find that the phase boundary between the interlayer…

We investigate properties of the lasing action observed on the 1S0--3P1 intercombination transition of ytterbium atoms that are laser-cooled and -trapped inside a high-finesse cavity. The dressing of the atomic states on the 1S0--1P1…

We studied optical coherence properties of the 1.53 $\mu$m telecommunication transition in an Er$^{3+}$-doped silicate optical fiber through spectral holeburning and photon echoes. We find decoherence times of up to 3.8 $\mu$s at a magnetic…

We report the observation of laser induced birefringence (LIB) in a wavelength-mismatched cascade system (J=0 \leftrightarrow J=1 \leftrightarrow J=0 transitions) of inhomogeneously broadened ytterbium atoms with strong pump and probe…

Quantum two-level systems (TLSs) are present in the materials of qubits and are considered defects because they limit qubit coherence. For superconducting qubits, the quintessential Josephson junction barrier is made of amorphous alumina,…

Two-level systems (TLS) are an important, if not dominant, source of loss and noise for superconducting resonators such as those used in kinetic inductance detectors and some quantum information science platforms. They are similarly…

The vortex lattice (VL) in the mixed state of the stannide superconductor Yb$_{3}$Rh$_{4}$Sn$_{13}$ has been studied using small-angle neutron scattering (SANS). The field dependencies of the normalized longitudinal and transverse…

Material disorders are one of the major sources of noise and loss in solid-state quantum devices, whose behaviors are often modeled as two-level systems (TLSs) formed by charge tunneling between neighboring sites. However, the role of their…