Phys.org May 14, 2024 Periodic temporal modulation of Hamiltonians can induce geometrical and topological phenomena in the dynamics of quantum states. Using the interference between two lasers an international team of researchers (Japan, USA – industry, Singapore, Australia, Germany) demonstrated an off-resonant optical lattice for a polariton condensate with controllable potential depths and nearest-neighbour coupling strength. Temporal modulation was introduced via a gigahertz frequency detuning between pump lasers, creating a polariton ‘conveyor belt’. The breaking of time-reversal symmetry caused band structures to become non-reciprocal and acquired a universal tilt. The non-reciprocal tilting was connected to the non-trivial topology of the […]
Tag Archives: Quantum states
Measuring the properties of light: Scientists realize new method for determining quantum states
Nanowerk February 25, 2024 Superconducting nanowire single-photon detectors (SNSPDs) have been widely used to study the discrete nature of quantum states of light in the form of photon-counting experiments. Researchers in Germany showed that SNSPDs can also be used to study continuous variables of optical quantum states by performing homodyne detection at a bandwidth of 400 kHz. By measuring the interference of a continuous-wave field of a local oscillator with the field of the vacuum state using two SNSPDs, they showed that the variance of the difference in count rates was linearly proportional to the photon flux of the local […]
Engineering the quantum states in solids using light
Science Daily March 30, 2022 In previous experiments, the light intensity for realizing Floquet state (where the original quantum state is replicated when light is irradiated on matters) in solids was enormous due to the high frequency of light. An international team of researchers (South Korea, Japan) succeeded in the experimental realization of the steady Floquet state in a graphene Josephson junction (GJJ) by irradiating continuous microwaves on it. The intensity of the light was decreased to one trillionth the value of previous experiments, significantly reducing the heat generation and enabling continuously long-lasting Floquet states. They also developed a novel […]