Measurements done on the quantum systems are too specific. Contrary to their
classical counterparts, quantum measurements can be invasive and destroy the
state of interest. Besides, quantumness limits the accuracy of measurements
done on quantum systems. Uncertainty relations define the universal accuracy
limit of the quantum measurements. Relatively recently, it was discovered that
quantum correlations and quantum memory might reduce the uncertainty of quantum
measurements. In the present work, we study two different types of measurements
done on the topological system. Namely, we discuss measurements done on the
spin operators and the canonical pair of operators: momentum and coordinate. We
quantify the spin operator's measurements through the entropic measures of
uncertainty and exploit the concept of quantum memory. While for the momentum
and coordinate operators, we exploit the improved uncertainty relations. We
discovered that quantum memory reduces the uncertainties of spin measurements.
On the hand, we proved that the uncertainties in the measurements of the
coordinate and momentum operators depend on the value of the momentum and are
substantially enhanced at small distances between itinerant and localized
electrons (the large momentum limit). We note that the topological nature of
the system leads to the spin-momentum locking. The momentum of the electron
depends on the spin and vice versa. Therefore, we suggest the indirect
measurement scheme for the momentum and coordinate operators through the spin
operator. Due to the factor of quantum memory, such indirect measurements in
topological insulators have smaller uncertainties rather than direct
measurements