Fig. 5: Demonstration of optical imaging of magnetoelectric quadrupole domains.
From: Imaging switchable magnetoelectric quadrupole domains via nonreciprocal linear dichroism
Microscopy images of a zero-field-cooled sample taken at 5 K using the X- (a) and the Y- (b) polarized light propagating along the +Z direction. Scale bar, 200 μm. c Linear dichroism (∆AXY) image obtained by calculating logarithmic subtraction of the image in a from b. The presence of contrast indicates a multidomain state of Q1 and Q2. In the region of lower and upper green boxes, the angles between the domain boundaries and the a axis are about 30° and 16°, respectively. d Profile of ∆AXY (left axis) and the fraction of domain Q1, f1, (right axis) along the green dashed line in c. The upper red (lower blue) line denotes a single domain state of Q1 (Q2). e ∆AXY images after cooling with four different sign combinations of poling fields (\(E_a^p = \pm \!0.57\) MV m−1, \(B_a^p = \pm \!0.1\) T). The poling fields are removed before taking each image. The absence of contrast shows the single domain of Q1 (Q2) in the (anti)parallel configuration of \(E_a^p\) and \(B_a^p\).
